diff --git a/Dockerfile b/Dockerfile
index e35627daf..c2df5eb17 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,7 @@ WORKDIR /usr/src/trwl
 RUN composer install --ignore-platform-reqs --no-interaction --no-progress --no-suggest --optimize-autoloader
 RUN php artisan optimize
 
-FROM php:8.3.9-apache
+FROM php:8.3.10-apache
 ENV APACHE_DOCUMENT_ROOT=/var/www/html/public
 
 RUN apt update && \
diff --git a/app/Console/Commands/DatabaseCleaner/DatabaseCleaner.php b/app/Console/Commands/DatabaseCleaner/DatabaseCleaner.php
index fc227ca59..96ee599b5 100644
--- a/app/Console/Commands/DatabaseCleaner/DatabaseCleaner.php
+++ b/app/Console/Commands/DatabaseCleaner/DatabaseCleaner.php
@@ -15,6 +15,7 @@ public function handle(): int {
         $this->call(Polylines::class);
         $this->call(PolylinesBrouter::class);
         $this->call(User::class);
+        $this->call(TrustedUser::class);
         $this->call(Trips::class);
 
         $this->call('queue-monitor:purge', ['--beforeDays' => 7]);
diff --git a/app/Console/Commands/DatabaseCleaner/TrustedUser.php b/app/Console/Commands/DatabaseCleaner/TrustedUser.php
new file mode 100644
index 000000000..de493fd0d
--- /dev/null
+++ b/app/Console/Commands/DatabaseCleaner/TrustedUser.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace App\Console\Commands\DatabaseCleaner;
+
+use App\Models\TrustedUser as TrustedUserModel;
+use Illuminate\Console\Command;
+
+class TrustedUser extends Command
+{
+    protected $signature   = 'app:clean-db:trusted-user';
+    protected $description = 'Find and delete expired trusted users from database';
+
+    public function handle(): int {
+        $affectedRows = TrustedUserModel::where('expires_at', '<', now())->delete();
+        $this->info($affectedRows . ' expired trusted users deleted.');
+        return 0;
+    }
+}
diff --git a/app/Enum/User/FriendCheckinSetting.php b/app/Enum/User/FriendCheckinSetting.php
new file mode 100644
index 000000000..a5a78a395
--- /dev/null
+++ b/app/Enum/User/FriendCheckinSetting.php
@@ -0,0 +1,20 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Enum\User;
+
+/**
+ * @OA\Schema(
+ *     title="FriendCheckinSetting",
+ *     type="string",
+ *     enum={"forbidden", "friends", "list"},
+ *     example="forbidden",
+ * )
+ */
+enum FriendCheckinSetting: string
+{
+    case FORBIDDEN = 'forbidden'; // default
+    case FRIENDS   = 'friends';   // user who are following each other
+    case LIST      = 'list';      // specific list of users
+}
+
diff --git a/app/Http/Controllers/API/v1/Controller.php b/app/Http/Controllers/API/v1/Controller.php
index 971bf083a..484fe166a 100644
--- a/app/Http/Controllers/API/v1/Controller.php
+++ b/app/Http/Controllers/API/v1/Controller.php
@@ -3,6 +3,8 @@
 namespace App\Http\Controllers\API\v1;
 
 use App\Models\OAuthClient;
+use App\Models\User;
+use Illuminate\Contracts\Auth\Authenticatable;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Support\Facades\Log;
 use Throwable;
@@ -137,4 +139,11 @@ public static function getCurrentOAuthClient(): OAuthClient|null {
             return null;
         }
     }
+
+    protected function getUserOrSelf(string|int $userIdOrSelf): Authenticatable {
+        if ($userIdOrSelf === 'self') {
+            return auth()->user();
+        }
+        return User::findOrFail($userIdOrSelf);
+    }
 }
diff --git a/app/Http/Controllers/API/v1/SettingsController.php b/app/Http/Controllers/API/v1/SettingsController.php
index 84085bd1e..61eff27e7 100644
--- a/app/Http/Controllers/API/v1/SettingsController.php
+++ b/app/Http/Controllers/API/v1/SettingsController.php
@@ -5,6 +5,7 @@
 use App\Enum\MapProvider;
 use App\Enum\MastodonVisibility;
 use App\Enum\StatusVisibility;
+use App\Enum\User\FriendCheckinSetting;
 use App\Exceptions\RateLimitExceededException;
 use App\Http\Controllers\Backend\SettingsController as BackendSettingsController;
 use App\Http\Resources\UserProfileSettingsResource;
@@ -63,39 +64,6 @@ public function updateMail(Request $request): UserProfileSettingsResource|JsonRe
         }
     }
 
-    public function resendMail(): void {
-        try {
-            auth()->user()->sendEmailVerificationNotification();
-            $this->sendResponse('', 204);
-        } catch (RateLimitExceededException) {
-            $this->sendError(error: __('email.verification.too-many-requests'), code: 429);
-        }
-    }
-
-    /**
-     * @throws ValidationException
-     */
-    public function updatePassword(Request $request): UserProfileSettingsResource|JsonResponse {
-        $userHasPassword = auth()->user()->password !== null;
-
-        $validated = $request->validate([
-                                            'currentPassword' => [Rule::requiredIf($userHasPassword)],
-                                            'password'        => ['required', 'string', 'min:8', 'confirmed']
-                                        ]);
-
-        if ($userHasPassword && !Hash::check($validated['currentPassword'], auth()->user()->password)) {
-            throw ValidationException::withMessages([__('controller.user.password-wrong')]);
-        }
-
-        $validated['password'] = Hash::make($validated['password']);
-
-        try {
-            return new UserProfileSettingsResource(BackendSettingsController::updateSettings($validated));
-        } catch (RateLimitExceededException) {
-            return $this->sendError(error: __('email.verification.too-many-requests'), code: 400);
-        }
-    }
-
     /**
      * @OA\Put(
      *     path="/settings/profile",
@@ -128,6 +96,13 @@ public function updatePassword(Request $request): UserProfileSettingsResource|Js
      *                   type="string",
      *                   nullable=true,
      *                   @OA\Schema(ref="#/components/schemas/MapProvider")
+     *               ),
+     *               @OA\Property(
+     *                  property="friendCheckin",
+     *                  type="string",
+     *                  nullable=true,
+     *                  @OA\Schema(ref="#/components/schemas/FriendCheckinSetting"),
+     *                  example="forbidden"
      *               )
      *         )
      *    ),
@@ -148,10 +123,9 @@ public function updatePassword(Request $request): UserProfileSettingsResource|Js
      */
     public function updateSettings(Request $request): UserProfileSettingsResource|JsonResponse {
         $validated = $request->validate([
-                                            'username'                => ['required',
-                                                                          'string',
-                                                                          'max:25',
-                                                                          'regex:/^[a-zA-Z0-9_]*$/'],
+                                            'username'                => [
+                                                'required', 'string', 'max:25', 'regex:/^[a-zA-Z0-9_]*$/'
+                                            ],
                                             'displayName'             => ['required', 'string', 'max:50'],
                                             'privateProfile'          => ['boolean', 'nullable'],
                                             'preventIndex'            => ['boolean', 'nullable'],
@@ -165,8 +139,42 @@ public function updateSettings(Request $request): UserProfileSettingsResource|Js
                                                 new Enum(MastodonVisibility::class),
                                             ],
                                             'mapProvider'             => ['nullable', new Enum(MapProvider::class)],
+                                            'friendCheckin'           => ['nullable', new Enum(FriendCheckinSetting::class)]
+                                        ]);
+
+        try {
+            return new UserProfileSettingsResource(BackendSettingsController::updateSettings($validated));
+        } catch (RateLimitExceededException) {
+            return $this->sendError(error: __('email.verification.too-many-requests'), code: 400);
+        }
+    }
+
+    public function resendMail(): void {
+        try {
+            auth()->user()->sendEmailVerificationNotification();
+            $this->sendResponse('', 204);
+        } catch (RateLimitExceededException) {
+            $this->sendError(error: __('email.verification.too-many-requests'), code: 429);
+        }
+    }
+
+    /**
+     * @throws ValidationException
+     */
+    public function updatePassword(Request $request): UserProfileSettingsResource|JsonResponse {
+        $userHasPassword = auth()->user()->password !== null;
+
+        $validated = $request->validate([
+                                            'currentPassword' => [Rule::requiredIf($userHasPassword)],
+                                            'password'        => ['required', 'string', 'min:8', 'confirmed']
                                         ]);
 
+        if ($userHasPassword && !Hash::check($validated['currentPassword'], auth()->user()->password)) {
+            throw ValidationException::withMessages([__('controller.user.password-wrong')]);
+        }
+
+        $validated['password'] = Hash::make($validated['password']);
+
         try {
             return new UserProfileSettingsResource(BackendSettingsController::updateSettings($validated));
         } catch (RateLimitExceededException) {
diff --git a/app/Http/Controllers/API/v1/TransportController.php b/app/Http/Controllers/API/v1/TransportController.php
index 41fc3b34a..eaa1f0874 100644
--- a/app/Http/Controllers/API/v1/TransportController.php
+++ b/app/Http/Controllers/API/v1/TransportController.php
@@ -2,7 +2,6 @@
 
 namespace App\Http\Controllers\API\v1;
 
-use App\Dto\Internal\CheckinSuccessDto;
 use App\Dto\Transport\Station as StationDto;
 use App\Enum\Business;
 use App\Enum\StatusVisibility;
@@ -10,20 +9,18 @@
 use App\Exceptions\Checkin\AlreadyCheckedInException;
 use App\Exceptions\CheckInCollisionException;
 use App\Exceptions\HafasException;
-use App\Exceptions\NotConnectedException;
 use App\Exceptions\StationNotOnTripException;
-use App\Http\Controllers\Backend\Transport\HomeController;
 use App\Http\Controllers\Backend\Transport\StationController;
 use App\Http\Controllers\Backend\Transport\TrainCheckinController;
 use App\Http\Controllers\HafasController;
 use App\Http\Controllers\TransportController as TransportBackend;
 use App\Http\Resources\CheckinSuccessResource;
 use App\Http\Resources\StationResource;
-use App\Http\Resources\StatusResource;
 use App\Http\Resources\TripResource;
 use App\Hydrators\CheckinRequestHydrator;
-use App\Models\Event;
 use App\Models\Station;
+use App\Models\User;
+use App\Notifications\YouHaveBeenCheckedIn;
 use Carbon\Carbon;
 use Exception;
 use Illuminate\Database\Eloquent\ModelNotFoundException;
@@ -332,9 +329,9 @@ public function getNextStationByCoordinates(Request $request): JsonResponse {
     /**
      * @OA\Post(
      *      path="/trains/checkin",
-     *      operationId="createTrainCheckin",
+     *      operationId="createCheckin",
      *      tags={"Checkin"},
-     *      summary="Create a checkin",
+     *      summary="Check in to a trip.",
      *      @OA\RequestBody(
      *          required=true,
      *          @OA\JsonContent(ref="#/components/schemas/CheckinRequestBody")
@@ -345,11 +342,11 @@ public function getNextStationByCoordinates(Request $request): JsonResponse {
      *          @OA\JsonContent(ref="#/components/schemas/CheckinSuccessResource")
      *       ),
      *       @OA\Response(response=400, description="Bad request"),
-     *       @OA\Response(response=409, description="Checkin collision"),
      *       @OA\Response(response=401, description="Unauthorized"),
+     *       @OA\Response(response=403, description="Forbidden", @OA\JsonContent(ref="#/components/schemas/CheckinForbiddenWithUsersResponse")),
+     *       @OA\Response(response=409, description="Checkin collision"),
      *       security={
      *           {"passport": {"create-statuses"}}, {"token": {}}
-     *
      *       }
      *     )
      *
@@ -372,13 +369,43 @@ public function create(Request $request): JsonResponse {
                                             'destination' => ['required', 'numeric'],
                                             'departure'   => ['required', 'date'],
                                             'arrival'     => ['required', 'date'],
-                                            'force'       => ['nullable', 'boolean']
+                                            'force'       => ['nullable', 'boolean'],
+                                            'with'        => ['nullable', 'array', 'max:10'],
                                         ]);
+        if (isset($validated['with'])) {
+            $withUsers      = User::whereIn('id', $validated['with'])->get();
+            $forbiddenUsers = collect();
+            foreach ($withUsers as $user) {
+                if (!Auth::user()?->can('checkin', $user)) {
+                    $forbiddenUsers->push($user);
+                }
+            }
+            if ($forbiddenUsers->isNotEmpty()) {
+                $forbiddenUserIds = $forbiddenUsers->pluck('id')->toArray();
+                return response()->json(
+                    data:   [
+                                'message' => 'You are not allowed to check in the following users: ' . implode(',', $forbiddenUserIds),
+                                'meta'    => [
+                                    'invalidUsers' => $forbiddenUserIds
+                                ]
+                            ],
+                    status: 403
+                );
+            }
+        }
 
         try {
-            $checkinResponse = TrainCheckinController::checkin((new CheckinRequestHydrator($validated))->hydrateFromApi());
+            $dto             = (new CheckinRequestHydrator($validated))->hydrateFromApi();
+            $checkinResponse = TrainCheckinController::checkin($dto);
+
+            // if isset, check in the other users with their default values
+            foreach ($withUsers ?? [] as $user) {
+                $dto->setUser($user);
+                $dto->setStatusVisibility($user->default_status_visibility);
+                $checkin = TrainCheckinController::checkin($dto);
+                $user->notify(new YouHaveBeenCheckedIn($checkin->status, auth()->user()));
+            }
 
-            //ToDo: Check if documented structure has changed
             return $this->sendResponse(new CheckinSuccessResource($checkinResponse), 201);
         } catch (CheckInCollisionException $exception) {
             return $this->sendError([
diff --git a/app/Http/Controllers/API/v1/TrustedUserController.php b/app/Http/Controllers/API/v1/TrustedUserController.php
new file mode 100644
index 000000000..c20fcb0c3
--- /dev/null
+++ b/app/Http/Controllers/API/v1/TrustedUserController.php
@@ -0,0 +1,108 @@
+<?php declare(strict_types=1);
+
+namespace App\Http\Controllers\API\v1;
+
+
+use App\Http\Resources\TrustedUserResource;
+use App\Models\TrustedUser;
+use App\Models\User;
+use Illuminate\Auth\Access\AuthorizationException;
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
+use Illuminate\Http\Response;
+
+class TrustedUserController extends Controller
+{
+
+    /**
+     * @OA\Get(
+     *     path="/user/{user}/trusted",
+     *     operationId="trustedUserIndex",
+     *     summary="Get all trusted users for a user",
+     *     description="Get all trusted users for the current user or a specific user (admin only).",
+     *     tags={"User"},
+     *     @OA\Parameter(name="user", in="path", required=true, description="ID of the user (or string 'self' for current user)", @OA\Schema(type="string")),
+     *     @OA\Response(response="200", description="List of trusted users"),
+     *     @OA\Response(response="401", description="Unauthorized"),
+     *     @OA\Response(response="403", description="Forbidden"),
+     *     @OA\Response(response="404", description="User not found"),
+     *     @OA\Response(response="500", description="Internal Server Error"),
+     * )
+     * @throws AuthorizationException
+     */
+    public function index(string|int $userIdOrSelf): AnonymousResourceCollection {
+        $user = $this->getUserOrSelf($userIdOrSelf);
+        $this->authorize('update', $user);
+        return TrustedUserResource::collection($user->trustedUsers()->orderBy('trusted_id')->cursorPaginate(10));
+    }
+
+    /**
+     * @OA\Post(
+     *     path="/user/{user}/trusted",
+     *     operationId="trustedUserStore",
+     *     summary="Add a user to the trusted users for a user",
+     *     description="Add a user to the trusted users for the current user or a specific user (admin only).",
+     *     tags={"User"},
+     *     @OA\Parameter(name="user", in="path", required=true, description="ID of the user (or string 'self' for current user) who want's to trust.", @OA\Schema(type="string")),
+     *     @OA\RequestBody(
+     *          required=true,
+     *          @OA\JsonContent(
+     *              required={"user_id"},
+     *              @OA\Property(property="userId", type="integer", example="1"),
+     *              @OA\Property(property="expiresAt", type="string", format="date-time", example="2024-07-28T00:00:00Z")
+     *          )
+     *     ),
+     *     @OA\Response(response="201", description="User added to trusted users"),
+     *     @OA\Response(response="400", description="Bad Request"),
+     *     @OA\Response(response="401", description="Unauthorized"),
+     *     @OA\Response(response="403", description="Forbidden"),
+     *     @OA\Response(response="404", description="User not found"),
+     *     @OA\Response(response="500", description="Internal Server Error"),
+     * )
+     * @throws AuthorizationException
+     */
+    public function store(Request $request, string|int $userIdOrSelf): Response {
+        $user        = $this->getUserOrSelf($userIdOrSelf);
+        $validated   = $request->validate([
+                                              'userId'    => ['required', 'exists:users,id'],
+                                              'expiresAt' => ['nullable', 'date', 'after:now'],
+                                          ]);
+        $trustedUser = User::find($validated['userId']);
+        $this->authorize('update', $user);
+        TrustedUser::updateOrCreate(
+            [
+                'user_id'    => $user->id,
+                'trusted_id' => $trustedUser->id,
+            ],
+            [
+                'expires_at' => $validated['expiresAt'] ?? null,
+            ]
+        );
+        return response()->noContent(201);
+    }
+
+    /**
+     * @OA\Delete(
+     *     path="/user/{user}/trusted/{trustedId}",
+     *     operationId="trustedUserDestroy",
+     *     summary="Remove a user from the trusted users for a user",
+     *     description="Remove a user from the trusted users for the current user or a specific user (admin only).",
+     *     tags={"User"},
+     *     @OA\Parameter(name="user", in="path", required=true, description="ID of the user (or string 'self' for current user)", @OA\Schema(type="string")),
+     *     @OA\Parameter(name="trusted", in="path", required=true, description="ID of the trusted user", @OA\Schema(type="integer")),
+     *     @OA\Response(response="204", description="User removed from trusted users"),
+     *     @OA\Response(response="401", description="Unauthorized"),
+     *     @OA\Response(response="403", description="Forbidden"),
+     *     @OA\Response(response="404", description="User not found"),
+     *     @OA\Response(response="500", description="Internal Server Error"),
+     * )
+     * @throws AuthorizationException
+     */
+    public function destroy(string|int $userIdOrSelf, int $trusted): Response {
+        $user    = $this->getUserOrSelf($userIdOrSelf);
+        $trusted = User::findOrFail($trusted);
+        $this->authorize('update', $user);
+        TrustedUser::where('user_id', $user->id)->where('trusted_id', $trusted->id)->delete();
+        return response()->noContent();
+    }
+}
diff --git a/app/Http/Controllers/Backend/User/FollowController.php b/app/Http/Controllers/Backend/User/FollowController.php
index fe1e5aea4..42b4ebfcf 100644
--- a/app/Http/Controllers/Backend/User/FollowController.php
+++ b/app/Http/Controllers/Backend/User/FollowController.php
@@ -118,9 +118,14 @@ public static function createOrRequestFollow(User $user, User $userToFollow): Us
                                      'user_id'   => $user->id,
                                      'follow_id' => $userToFollow->id
                                  ]);
-        $userToFollow->fresh();
+        $userToFollow->refresh();
         $userToFollow->notify(new UserFollowed($follow));
         Cache::forget(CacheKey::getFriendsLeaderboardKey($user->id));
         return $userToFollow;
     }
+
+    public static function isFollowingEachOther(User $user, User $otherUser): bool {
+        return $user->userFollowers->contains('id', $otherUser->id)
+               && $user->userFollowings->contains('id', $otherUser->id);
+    }
 }
diff --git a/app/Http/Resources/TrustedUserResource.php b/app/Http/Resources/TrustedUserResource.php
new file mode 100644
index 000000000..3602787d6
--- /dev/null
+++ b/app/Http/Resources/TrustedUserResource.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Http\Resources;
+
+use Illuminate\Http\Resources\Json\JsonResource;
+
+/**
+ * @OA\Schema(
+ *     title="TrustedUser",
+ *     @OA\Property(property="user", ref="#/components/schemas/LightUserResource"),
+ *     @OA\Property(property="expiresAt", type="string", format="date-time", example="2024-07-28T00:00:00Z")
+ * )
+ */
+class TrustedUserResource extends JsonResource
+{
+    public function toArray($request): array {
+        return [
+            'user'      => new LightUserResource($this->trusted),
+            'expiresAt' => $this->expires_at?->toIso8601String()
+        ];
+    }
+}
diff --git a/app/Http/Resources/UserBaseResource.php b/app/Http/Resources/UserBaseResource.php
index ed6bd1ec1..ce1490fee 100644
--- a/app/Http/Resources/UserBaseResource.php
+++ b/app/Http/Resources/UserBaseResource.php
@@ -29,7 +29,8 @@ public function toArray($request): array {
                 [
                     'home'                    => $this->home,
                     'language'                => $this->language,
-                    'defaultStatusVisibility' => $this->default_status_visibility
+                    'defaultStatusVisibility' => $this->default_status_visibility,
+                    'friendCheckin'           => $this->friend_checkin,
                 ]),
             $this->mergeWhen(isset($this->UserResource),
                 [
diff --git a/app/Models/TrustedUser.php b/app/Models/TrustedUser.php
new file mode 100644
index 000000000..d7e1723f5
--- /dev/null
+++ b/app/Models/TrustedUser.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace App\Models;
+
+use Carbon\Carbon;
+use Illuminate\Database\Eloquent\Concerns\HasUuids;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+/**
+ * // properties
+ * @property string      id
+ * @property integer     user_id
+ * @property integer     trusted_id
+ * @property Carbon|null expires_at
+ * @property Carbon      created_at
+ * @property Carbon      updated_at
+ *
+ * // relationships
+ * @property User        user
+ * @property User        trusted
+ */
+class TrustedUser extends Model
+{
+    use HasUuids;
+
+    protected $keyType      = 'string';
+    public    $incrementing = false;
+    protected $fillable     = ['user_id', 'trusted_id', 'expires_at'];
+    protected $casts        = [
+        'id'         => 'string',
+        'user_id'    => 'integer',
+        'trusted_id' => 'integer',
+        'expires_at' => 'datetime',
+    ];
+
+    public function trusted(): BelongsTo {
+        return $this->belongsTo(User::class, 'trusted_id', 'id');
+    }
+}
diff --git a/app/Models/User.php b/app/Models/User.php
index da1e002ac..6759f6d4c 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -4,6 +4,7 @@
 
 use App\Enum\MapProvider;
 use App\Enum\StatusVisibility;
+use App\Enum\User\FriendCheckinSetting;
 use App\Exceptions\RateLimitExceededException;
 use App\Http\Controllers\Backend\Social\MastodonProfileDetails;
 use App\Jobs\SendVerificationEmail;
@@ -18,6 +19,7 @@
 use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\DatabaseNotification;
 use Illuminate\Notifications\Notifiable;
+use Illuminate\Support\Collection;
 use Illuminate\Support\Facades\Log;
 use Illuminate\Support\Facades\RateLimiter;
 use Laravel\Passport\HasApiTokens;
@@ -25,36 +27,56 @@
 use Spatie\Permission\Traits\HasRoles;
 
 /**
- * @property int                id
- * @property string             username
- * @property string             name
- * @property string             avatar
- * @property string             email
- * @property Carbon             email_verified_at
- * @property string             password
- * @property int                home_id
- * @property Carbon             privacy_ack_at
- * @property integer            default_status_visibility
- * @property boolean            private_profile
- * @property boolean            prevent_index
- * @property boolean            likes_enabled
- * @property boolean            points_enabled
- * @property MapProvider        mapprovider
- * @property int                privacy_hide_days
- * @property string             language
- * @property Carbon             last_login
- * @property Status[]           $statuses
- * @property SocialLoginProfile socialProfile
- * @property int                points
- * @property boolean            userInvisibleToMe
- * @property string             mastodonUrl
- * @property int                train_distance
- * @property int                train_duration
- * @property boolean            following
- * @property boolean            followPending
- * @property boolean            muted
- * @property boolean            isAuthUserBlocked
- * @property boolean            isBlockedByAuthUser
+ * // properties
+ * @property int                  id
+ * @property string               username
+ * @property string               name
+ * @property string               avatar
+ * @property string               email
+ * @property Carbon               email_verified_at
+ * @property string               password
+ * @property int                  home_id
+ * @property Carbon               privacy_ack_at
+ * @property StatusVisibility     default_status_visibility
+ * @property boolean              private_profile
+ * @property boolean              prevent_index
+ * @property boolean              likes_enabled
+ * @property boolean              points_enabled
+ * @property MapProvider          mapprovider
+ * @property string               timezone
+ * @property FriendCheckinSetting friend_checkin
+ * @property int                  privacy_hide_days
+ * @property string               language
+ * @property Carbon               last_login
+ * @property int                  points
+ * @property boolean              userInvisibleToMe
+ * @property string               mastodonUrl
+ * @property int                  train_distance
+ * @property int                  train_duration
+ * @property boolean              following
+ * @property boolean              followPending
+ * @property boolean              muted
+ * @property boolean              isAuthUserBlocked
+ * @property boolean              isBlockedByAuthUser
+ *
+ * // relationships
+ * @property Collection           trainCheckins
+ * @property SocialLoginProfile   socialProfile
+ * @property Station              home
+ * @property Collection           likes
+ * @property Collection           follows
+ * @property Collection           blockedUsers
+ * @property Collection           blockedByUsers
+ * @property Collection           mutedUsers
+ * @property Collection           followRequests
+ * @property Collection           userFollowers
+ * @property Collection           userFollowings
+ * @property Collection           sessions
+ * @property Collection           icsTokens
+ * @property Collection           webhooks
+ * @property Collection           notifications
+ * @property Collection           statuses
+ * @property Collection           trustedUsers
  *
  *
  * @todo rename home_id to home_station_id
@@ -69,7 +91,7 @@ class User extends Authenticatable implements MustVerifyEmail
     protected $fillable = [
         'username', 'name', 'avatar', 'email', 'email_verified_at', 'password', 'home_id', 'privacy_ack_at',
         'default_status_visibility', 'likes_enabled', 'points_enabled', 'private_profile', 'prevent_index',
-        'privacy_hide_days', 'language', 'last_login', 'mapprovider', 'timezone',
+        'privacy_hide_days', 'language', 'last_login', 'mapprovider', 'timezone', 'friend_checkin',
     ];
     protected $hidden   = [
         'password', 'remember_token', 'email', 'email_verified_at', 'privacy_ack_at',
@@ -92,16 +114,14 @@ class User extends Authenticatable implements MustVerifyEmail
         'privacy_hide_days'         => 'integer',
         'last_login'                => 'datetime',
         'mapprovider'               => MapProvider::class,
+        'timezone'                  => 'string',
+        'friend_checkin'            => FriendCheckinSetting::class,
     ];
 
     public function getTrainDistanceAttribute(): float {
         return Checkin::where('user_id', $this->id)->sum('distance');
     }
 
-    public function statuses(): HasMany {
-        return $this->hasMany(Status::class);
-    }
-
     public function trainCheckins(): HasMany {
         return $this->hasMany(Checkin::class, 'user_id', 'id');
     }
@@ -150,14 +170,14 @@ public function followRequests(): HasMany {
     }
 
     /**
-     * @deprecated
+     * @deprecated use ->userFollowers instead to get the users directly
      */
     public function followers(): HasMany {
         return $this->hasMany(Follow::class, 'follow_id', 'id');
     }
 
     /**
-     * @deprecated
+     * @deprecated use ->userFollowing instead to get the users directly
      */
     public function followings(): HasMany {
         return $this->hasMany(Follow::class, 'user_id', 'id');
@@ -182,18 +202,20 @@ public function getPointsAttribute(): int {
                       ->sum('points');
     }
 
-    /**
-     * @untested
-     * @todo test
-     */
+    public function statuses(): HasMany {
+        return $this->hasMany(Status::class);
+    }
+
+    public function trustedUsers(): HasMany {
+        return $this->hasMany(TrustedUser::class, 'user_id', 'id')
+                    ->with(['trusted'])
+                    ->whereNull('expires_at')->orWhere('expires_at', '>', now());
+    }
+
     public function userFollowings(): BelongsToMany {
         return $this->belongsToMany(__CLASS__, 'follows', 'user_id', 'follow_id');
     }
 
-    /**
-     * @untested
-     * @todo test
-     */
     public function userFollowers(): BelongsToMany {
         return $this->belongsToMany(__CLASS__, 'follows', 'follow_id', 'user_id');
     }
diff --git a/app/Notifications/YouHaveBeenCheckedIn.php b/app/Notifications/YouHaveBeenCheckedIn.php
new file mode 100644
index 000000000..86e9d0fbf
--- /dev/null
+++ b/app/Notifications/YouHaveBeenCheckedIn.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Models\Status;
+use App\Models\User;
+use Illuminate\Bus\Queueable;
+use Illuminate\Notifications\Notification;
+
+class YouHaveBeenCheckedIn extends Notification implements BaseNotification
+{
+    use Queueable;
+
+    private Status $status;
+    private User   $userCheckedIn;
+
+    public function __construct(Status $status, User $userCheckedIn) {
+        $this->status        = $status;
+        $this->userCheckedIn = $userCheckedIn;
+    }
+
+    public function via(): array {
+        return ['database'];
+    }
+
+    public function toArray(): array {
+        return [
+            'status'  => $this->status->only(['id']),
+            'checkin' => [
+                'line'        => $this->status->checkin->trip->linename,
+                'origin'      => $this->status->checkin->originStopover->station->name,
+                'destination' => $this->status->checkin->destinationStopover->station->name,
+            ],
+            'user'    => $this->userCheckedIn->only(['id', 'username', 'name']),
+        ];
+    }
+
+    public static function getLead(array $data): string {
+        return __('notifications.youHaveBeenCheckedIn.lead', [
+            'username' => $data['user']['username'],
+        ]);
+    }
+
+    public static function getNotice(array $data): ?string {
+        return __('notifications.userJoinedConnection.notice', [
+                                                                 'line'        => $data['checkin']['line'],
+                                                                 'origin'      => $data['checkin']['origin'],
+                                                                 'destination' => $data['checkin']['destination'],
+                                                             ]
+        );
+    }
+
+    public static function getLink(array $data): ?string {
+        return route('status', ['id' => $data['status']['id']]);
+    }
+}
diff --git a/app/Policies/UserPolicy.php b/app/Policies/UserPolicy.php
index de790f832..c52f3c7dd 100644
--- a/app/Policies/UserPolicy.php
+++ b/app/Policies/UserPolicy.php
@@ -2,7 +2,9 @@
 
 namespace App\Policies;
 
+use App\Enum\User\FriendCheckinSetting;
 use App\Http\Controllers\Backend\User\BlockController;
+use App\Http\Controllers\Backend\User\FollowController;
 use App\Models\User;
 use Illuminate\Auth\Access\HandlesAuthorization;
 use Illuminate\Auth\Access\Response;
@@ -64,7 +66,7 @@ public function view(?User $user, User $model): Response {
      * @return bool
      */
     public function update(User $user, User $model): bool {
-        return $user->id === $model->id;
+        return $user->id === $model->id || $user->hasRole('admin');
     }
 
     /**
@@ -78,4 +80,25 @@ public function update(User $user, User $model): bool {
     public function delete(User $user, User $model): bool {
         return $user->id === $model->id;
     }
+
+    /**
+     * Check if user can check in another user
+     *
+     * @param User $user
+     * @param User $userToCheckin
+     *
+     * @return bool
+     */
+    public function checkin(User $user, User $userToCheckin): bool {
+        if ($userToCheckin->friend_checkin === FriendCheckinSetting::FORBIDDEN) {
+            return false;
+        }
+        if ($userToCheckin->friend_checkin === FriendCheckinSetting::FRIENDS) {
+            return FollowController::isFollowingEachOther($user, $userToCheckin);
+        }
+        if ($userToCheckin->friend_checkin === FriendCheckinSetting::LIST) {
+            return $userToCheckin->trustedUsers->contains('trusted_id', $user->id);
+        }
+        return $user->is($userToCheckin);
+    }
 }
diff --git a/app/Virtual/Models/CheckinRequestBody.php b/app/Virtual/Models/CheckinRequestBody.php
index 4044d6701..4bad40506 100644
--- a/app/Virtual/Models/CheckinRequestBody.php
+++ b/app/Virtual/Models/CheckinRequestBody.php
@@ -2,161 +2,29 @@
 
 namespace App\Virtual\Models;
 
-use Carbon\Carbon;
-
 /**
  * @OA\Schema(
  *     title="CheckinRequestBody",
  *     description="Fields for creating a train checkin",
- *     @OA\Xml(
- *         name="CheckinRequestBody"
- *     )
+ *     @OA\Property(property="body", type="string", maxLength=280, nullable=true, example="Meine erste Fahrt nach Knuffingen!"),
+ *     @OA\Property(property="business", ref="#/components/schemas/Business",),
+ *     @OA\Property(property="visibility", ref="#/components/schemas/StatusVisibility",),
+ *     @OA\Property(property="eventId", type="integer", nullable=true, example="1", description="Id of an event the status should be connected to"),
+ *     @OA\Property(property="toot", type="boolean", nullable=true, example="false", description="Should this status be posted to mastodon?"),
+ *     @OA\Property(property="chainPost", type="boolean", nullable=true, example="false", description="Should this status be posted to mastodon as a chained post?"),
+ *     @OA\Property(property="ibnr", type="boolean", nullable=true, example="true", description="If true, the `start` and `destination` properties can be supplied as an ibnr. Otherwise they should be given as the Träwelling-ID. Default behavior is `false`."),
+ *     @OA\Property(property="tripId", type="string", nullable=true, example="b37ff515-22e1-463c-94de-3ad7964b5cb8", description="The tripId for the to be checked in train"),
+ *     @OA\Property(property="lineName", type="string", nullable=true, example="S 4", description="The line name for the to be checked in train"),
+ *     @OA\Property(property="start", type="integer", example="8000191", description="The Station-ID of the starting point (see `ibnr`)"),
+ *     @OA\Property(property="destination", type="integer", example="8000192", description="The Station-ID of the destination point (see `ibnr`)"),
+ *     @OA\Property(property="departure", type="string", format="date-time", example="2022-12-19T20:41:00+01:00", description="Timestamp of the departure"),
+ *     @OA\Property(property="arrival", type="string", format="date-time", example="2022-12-19T20:42:00+01:00", description="Timestamp of the arrival"),
+ *     @OA\Property(property="force", type="boolean", nullable=true, example="false", description="If true, the checkin will be created, even if a colliding checkin exists. No points will be awarded."),
+ *     @OA\Property(property="with", type="array", @OA\Items(type="integer", example="1"), example="[1, 2]", nullable=true, description="If set, the checkin will be created for all given users as well. The user creating the checkin must be allowed to checkin for the other users. Max. 10 users."),
  * )
  */
 class CheckinRequestBody
 {
-    /**
-     * @OA\Property(
-     *     title="body",
-     *     description="Text that should be added to the post",
-     *     type="string",
-     *     maxLength=280,
-     *     nullable=true,
-     *     example="Meine erste Fahrt nach Knuffingen!"
-     * )
-     *
-     * @var string
-     */
-    private $body;
-
-    /**
-     * @OA\Property (
-     *     ref="#/components/schemas/Business",
-     * )
-     *
-     * @var integer
-     */
-    private $business;
-
-    /**
-     * @OA\Property (
-     *      ref="#/components/schemas/StatusVisibility"
-     * )
-     *
-     * @var integer
-     */
-    private $visibility;
-
-    /**
-     * @OA\Property (
-     *     title="eventId",
-     *     nullable=true,
-     *     description="Id of an event the status should be connected to",
-     *     type="integer"
-     * )
-     */
-    private $eventId;
-
-    /**
-     * @OA\Property (
-     *     title="toot",
-     *     nullable=true,
-     *     description="Should this status be posted to mastodon?",
-     *     type="boolean",
-     *     example="false"
-     * )
-     */
-    private $toot;
-
-    /**
-     * @OA\Property (
-     *     title="chainPost",
-     *     nullable=true,
-     *     description="Should this status be posted to mastodon as a chained post?",
-     *     type="boolean",
-     *     example="false"
-     * )
-     */
-    private $chainPost;
-
-    /**
-     * @OA\Property (
-     *     title="ibnr",
-     *     nullable=true,
-     *     description="If true, the `start` and `destination` properties can be supplied as an ibnr. Otherwise they
-     *     should be given as the Träwelling-ID. Default behavior is `false`.", type="boolean", example="true",
-     * )
-     */
-    private $ibnr;
-
-    /**
-     * @OA\Property (
-     *     title="tripId",
-     *     description="The HAFAS tripId for the to be checked in train",
-     *     example="1|323306|1|80|17072022"
-     * )
-     */
-    private $tripId;
-
-    /**
-     * @OA\Property (
-     *     title="lineName",
-     *     description="The line name for the to be checked in train",
-     *     example="S 4"
-     * )
-     */
-    private $lineName;
-
-    /**
-     * @OA\Property (
-     *     title="start",
-     *     description="The Station-ID of the starting point (see `ibnr`)",
-     *     example="8000191",
-     *     type="integer"
-     * )
-     */
-    private $start;
-
-    /**
-     * @OA\Property (
-     *     title="destination",
-     *     description="The Station-ID of the destination (see `ibnr`)",
-     *     example="8079045",
-     *     type="integer"
-     * )
-     */
-    private $destination;
-
-    /**
-     * @OA\Property (
-     *     title="departure",
-     *     description="Timestamp of the departure",
-     *     example="2022-12-19T20:41:00+01:00",
-     * )
-     *
-     * @var Carbon
-     */
-    private $departure;
-
-    /**
-     * @OA\Property (
-     *     title="arrival",
-     *     description="Timestamp of the arrival",
-     *     example="2022-12-19T20:42:00+01:00",
-     * )
-     *
-     * @var Carbon
-     */
-    private $arrival;
 
-    /**
-     * @OA\Property (
-     *     title="force",
-     *     nullable=true,
-     *     description="If true, the checkin will be created, even if a colliding checkin exists. No points will be
-     *     awarded.", type="boolean", example="false",
-     * )
-     */
-    private $force;
 
 }
diff --git a/app/Virtual/Models/Response/CheckinForbiddenWithUsersResponse.php b/app/Virtual/Models/Response/CheckinForbiddenWithUsersResponse.php
new file mode 100644
index 000000000..c0e2cc296
--- /dev/null
+++ b/app/Virtual/Models/Response/CheckinForbiddenWithUsersResponse.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Virtual\Models\Response;
+
+/**
+ * @OA\Schema(
+ *      title="CheckinForbiddenWithUsersResponse",
+ *      @OA\Property (
+ *          property="message",
+ *          example="You are not allowed to check in the following users: 1"
+ *      ),
+ *      @OA\Property (
+ *          property="meta",
+ *          type="object",
+ *          @OA\Property (
+ *              property="invalidUsers",
+ *              type="array",
+ *              @OA\Items(
+ *                  type="integer",
+ *                  example="1"
+ *              )
+ *          )
+ *     )
+ * )
+ */
+class CheckinForbiddenWithUsersResponse
+{
+}
diff --git a/database/migrations/2024_06_28_000000_add_friend_checkin_setting_to_users.php b/database/migrations/2024_06_28_000000_add_friend_checkin_setting_to_users.php
new file mode 100644
index 000000000..cbe136b96
--- /dev/null
+++ b/database/migrations/2024_06_28_000000_add_friend_checkin_setting_to_users.php
@@ -0,0 +1,20 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void {
+        Schema::table('users', function(Blueprint $table) {
+            $table->string('friend_checkin')->default('forbidden')->after('timezone');
+        });
+    }
+
+    public function down(): void {
+        Schema::table('users', function(Blueprint $table) {
+            $table->dropColumn('friend_checkin');
+        });
+    }
+};
diff --git a/database/migrations/2024_07_28_000001_add_trusted_users_table.php b/database/migrations/2024_07_28_000001_add_trusted_users_table.php
new file mode 100644
index 000000000..7bec63e32
--- /dev/null
+++ b/database/migrations/2024_07_28_000001_add_trusted_users_table.php
@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void {
+        Schema::create('trusted_users', static function(Blueprint $table) {
+            $table->uuid('id')->primary();
+
+            $table->foreignId('user_id')->constrained('users')->onDelete('cascade');
+            $table->foreignId('trusted_id')->constrained('users')->onDelete('cascade');
+            $table->timestamp('expires_at')->nullable();
+
+            $table->timestamps();
+
+            $table->unique(['user_id', 'trusted_id']);
+
+            $table->comment('This table is used to store trusted users for friend checkin.');
+        });
+    }
+
+    public function down(): void {
+        Schema::dropIfExists('trusted_users');
+    }
+};
diff --git a/lang/de.json b/lang/de.json
index 8c89c4820..8c835ac2a 100644
--- a/lang/de.json
+++ b/lang/de.json
@@ -146,6 +146,7 @@
     "events.request-button": "Melden",
     "events.notice": "Deine Meldung wird nur veröffentlicht, wenn das Träwelling-Team sie freigegeben hat.",
     "events.request.success": "Dein Vorschlag ist bei uns angekommen. Vielen Dank!",
+    "events.show-all-for-event": "Alle Check-ins zum Event anzeigen",
     "event": "Veranstaltung",
     "events": "Veranstaltungen",
     "auth.required": "Du musst eingeloggt sein, um diese Funktion nutzen zu können.",
@@ -763,5 +764,7 @@
     "action.error": "Diese Aktion konnte leider nicht ausgeführt werden. Bitte versuche es später noch einmal.",
     "action.like": "Status liken",
     "action.dislike": "Status nicht mehr liken",
-    "action.set-home": "Heimathaltestelle setzen"
+    "action.set-home": "Heimathaltestelle setzen",
+    "notifications.youHaveBeenCheckedIn.lead": "Du wurdest von :username eingecheckt",
+    "notifications.youHaveBeenCheckedIn.notice": "Fahrt in :line von :origin nach :destination"
 }
diff --git a/lang/en.json b/lang/en.json
index 2ebd3aa7c..d000b00a3 100644
--- a/lang/en.json
+++ b/lang/en.json
@@ -128,6 +128,7 @@
     "events.live": "Live Events",
     "events.past": "Past Events",
     "events.new": "Create Event",
+    "events.show-all-for-event": "Show all check-ins for this event",
     "export.begin": "Start",
     "export.btn": "Export data",
     "export.end": "End",
@@ -228,6 +229,8 @@
     "notifications.statusLiked.lead": "<b>@:likerUsername</b> liked your check-in.",
     "notifications.statusLiked.notice": "Journey in :line on :createdDate|Journey in line :line on :createdDate",
     "notifications.userFollowed.lead": "<b>@:followerUsername</b> follows you now.",
+    "notifications.youHaveBeenCheckedIn.lead": "You have been checked in by <b>@:username</b>",
+    "notifications.youHaveBeenCheckedIn.notice": "Journey in :line from :origin to :destination",
     "notifications.userRequestedFollow.lead": "<b>@:followerRequestUsername</b> wants to follow you.",
     "notifications.userRequestedFollow.notice": "To accept or decline the follow request, click here or go to your settings.",
     "notifications.userApprovedFollow.lead": "<b>@:followerRequestUsername</b> has approved your follow request.",
diff --git a/resources/sass/app-dark.scss b/resources/sass/app-dark.scss
index b33f607e4..af5247644 100644
--- a/resources/sass/app-dark.scss
+++ b/resources/sass/app-dark.scss
@@ -1,4 +1,5 @@
 @import "variables";
+@import "mdb-ui-kit/src/scss/free/_variables";
 
 :root.dark {
     --mdb-body-color: #{$dm-body};
@@ -6,12 +7,16 @@
 
     --mdb-link-color: #{$dm-lightblue};
     --mdb-btn-hover-color: #{$dm-lightblue};
-    --mdb-btn-hover-color: #{$dm-lightblue};
     --mdb-btn-focus-color: #{$dm-lightblue};
     --mdb-btn-active-color: #{$dm-lightblue};
 
     --mdb-nav-tabs-link-color: $dm-lightblue;
 
+    $box-shadow: 0 0.5rem 1rem rgba($gray-300, 0.15) !default;
+    $box-shadow-sm: 0 0.125rem 0.25rem rgba($gray-300, 0.075) !default;
+    $box-shadow-lg: 0 1rem 3rem rgba($gray-300, 0.175) !default;
+    $box-shadow-inset: inset 0 1px 2px rgba($gray-300, 0.075) !default;
+
     body {
         background-color: $dm-base;
         color: $dm-body !important;
@@ -46,6 +51,7 @@
         background-color: lighten($dm-base, 2%);
         border-color: lighten($dm-base, 30%) !important;
         color: lighten($dm-body, 8%) !important;
+
         &:focus {
             background-color: lighten($dm-base, 10%);
         }
@@ -55,6 +61,7 @@
         background-color: lighten($dm-base, 2%);
         color: $dm-body !important;
         border-color: lighten($dm-base, 30%) !important;
+
         &:focus {
             background-color: lighten($dm-base, 10%);
         }
@@ -116,6 +123,7 @@
         background: lighten($dm-base, 30%) !important;
         border-color: $dm-trwlRot-shape;
     }
+
     .text-trwl {
         color: $dm-trwlRot !important;
     }
@@ -130,16 +138,17 @@
         .progress {
             .progress-bar {
                 background: $dm-trwlRot-shape;
+
                 &.progress-pride {
                     background: linear-gradient(
-                        66deg,
-                        hsl(0, 75%, 60%) 0 14.28%,
-                        hsl(39, 75%, 47%) 0 28.57%,
-                        hsl(60, 65%, 50%) 0 42.85%,
-                        hsl(120, 75%, 40%) 0 57.14%,
-                        hsl(181, 75%, 40%) 0 71.42%,
-                        hsl(240, 75%, 60%) 0 85.71%,
-                        hsl(275, 75%, 35%) 0
+                            66deg,
+                            hsl(0, 75%, 60%) 0 14.28%,
+                            hsl(39, 75%, 47%) 0 28.57%,
+                            hsl(60, 65%, 50%) 0 42.85%,
+                            hsl(120, 75%, 40%) 0 57.14%,
+                            hsl(181, 75%, 40%) 0 71.42%,
+                            hsl(240, 75%, 60%) 0 85.71%,
+                            hsl(275, 75%, 35%) 0
                     );
                 }
             }
@@ -281,6 +290,7 @@
     .list-group-item {
         background-color: lighten($dm-base, 15%);
         color: $dm-body !important;
+
         &:hover {
             background-color: lighten($dm-base, 10%);
         }
@@ -338,6 +348,7 @@
     .alert-info {
         background-color: hsl(194, 80%, 20%);
         color: rgb(238, 238, 238);
+
         i {
             color: hsl(195, 63%, 70%);
         }
@@ -362,8 +373,8 @@
         background: linear-gradient(
                 #{rgba(darken($dm-trwlRot, 60%), 0.4)},
                 #{rgba(darken($dm-trwlRot, 60%), 0.4)}
-            ),
-            url("/images/covers/profile-background.png");
+        ),
+        url("/images/covers/profile-background.png");
         background-position: center;
     }
 
@@ -373,8 +384,7 @@
         --mdb-pagination-hover-border-color: #{$dm-base-20} !important;
         --mdb-pagination-focus-color: #{$dm-body} !important;
         --mdb-pagination-focus-bg: #{$dm-base-30} !important;
-        --mdb-pagination-focus-box-shadow: 0 0 0 0.25rem
-            rgba(59, 113, 202, 0.25);
+        --mdb-pagination-focus-box-shadow: 0 0 0 0.25rem rgba(59, 113, 202, 0.25);
         --mdb-pagination-active-color: #{$dm-body} !important;
         --mdb-pagination-active-bg: #{$dm-base-30} !important;
         --mdb-pagination-active-border-color: #{$dm-base-30} !important;
@@ -382,9 +392,11 @@
         --mdb-pagination-disabled-bg: #{$dm-base} !important;
         --mdb-pagination-disabled-border-color: #{$dm-base} !important;
     }
+
     a.page-link {
         color: #{$dm-body} !important;
     }
+
     .page-item {
         &.disabled {
             .page-link {
@@ -425,9 +437,9 @@
 
     .leaflet-layer {
         &:nth-child(1) .leaflet-tile {
-            filter: invert(1) grayscale(100%) sepia(100%) hue-rotate(180deg)
-                saturate(0.7);
+            filter: invert(1) grayscale(100%) sepia(100%) hue-rotate(180deg) saturate(0.7);
         }
+
         &:nth-child(2) .leaflet-tile {
             filter: invert(1) hue-rotate(180deg) grayscale(70%) opacity(0.65);
         }
@@ -441,4 +453,8 @@
     .leaflet-interactive {
         stroke: $dm-trwlRot-shape;
     }
+
+    .shadow-sm {
+        box-shadow: $box-shadow-sm !important;
+    }
 }
diff --git a/resources/views/settings/profile.blade.php b/resources/views/settings/profile.blade.php
index c9bdd5868..ce7a8b78f 100644
--- a/resources/views/settings/profile.blade.php
+++ b/resources/views/settings/profile.blade.php
@@ -23,11 +23,11 @@
                                     />
                                 </div>
 
-                                <a href="#" class="btn btn-primary mb-3" data-mdb-toggle="modal"
+                                <a href="#" class="btn btn-primary mb-1" data-mdb-toggle="modal"
                                    data-mdb-target="#uploadAvatarModal">
                                     {{__('settings.upload-image')}}
                                 </a>
-
+                                <br/>
                                 <a href="javascript:void(0)"
                                    class="btn btn-outline-danger btn-sm mb-3 {{isset(auth()->user()->avatar) ? '' : 'd-none'}}"
                                    id="btnModalDeleteProfilePicture"
diff --git a/resources/vue/components/ActiveJourneyMap.vue b/resources/vue/components/ActiveJourneyMap.vue
index cd07d17b8..946a443dd 100644
--- a/resources/vue/components/ActiveJourneyMap.vue
+++ b/resources/vue/components/ActiveJourneyMap.vue
@@ -8,6 +8,8 @@
 
 <script>
 import 'leaflet';
+import {trans} from "laravel-vue-i18n";
+import {DtmRange} from "../helpers/DateRange";
 
 import('Leaflet-MovingMaker/MovingMarker');
 
@@ -66,6 +68,7 @@ export default {
         }
     },
     methods: {
+        trans,
         renderMap() {
             this.map = L.map(this.$refs.map, {
                 center: [50.3, 10.47],
@@ -148,11 +151,13 @@ export default {
                 icon: eventIcon
             }).addTo(this.map);
 
+            const range = DtmRange.fromISO(event.begin, event.end);
+
             marker.bindPopup(`
                 <strong><a href="${event.url}">${event.name}</a></strong><br />
                 <i class="fa fa-user-clock"></i> ${event.host}<br />
-                <i class="fa fa-calendar-day"></i> ${event.begin} - ${event.end}<br />
-                <a href="/event/${event.slug}">Alle Reisen zum Event anzeigen</a>`
+                <i class="fa fa-calendar-day"></i> ${range.toLocaleDateString()}<br />
+                <a href="/event/${event.slug}">${trans('events.show-all-for-event')}</a>`
             );
         },
         getIconForStatus(response) {
diff --git a/resources/vue/components/ActiveStatusCard.vue b/resources/vue/components/ActiveStatusCard.vue
index fd8159ebd..85b1199f2 100644
--- a/resources/vue/components/ActiveStatusCard.vue
+++ b/resources/vue/components/ActiveStatusCard.vue
@@ -64,7 +64,7 @@ export default defineComponent({
     },
     mounted() {
         this.fetchState();
-        setTimeout(this.getNextStation,500);
+        setTimeout(this.getNextStation, 500);
         this.fetchInterval = setInterval(this.fetchState, 30000);
         this.nextStationInterval = setInterval(this.getNextStation, 10000);
     },
@@ -81,13 +81,14 @@ export default defineComponent({
 
 <template>
     <div v-show="showCard" class="fab-container d-md-none">
-        <div class="card hover-card w-75 shadow-3" @click="goToStatus">
+        <div class="card hover-card w-100 shadow-sm" @click="goToStatus">
             <div class="card-body py-2 px-3">
                 <p class="mb-0">{{ state.status?.train?.origin?.name }} <small
                     class="float-end text-muted">{{ format(departure) }}</small></p>
 
                 <p class="ms-2 col-auto align-items-center d-flex my-0" v-show="state.status?.train?.lineName">
-                    <LineIndicator :product-name="state.status?.train?.category" :number="state.status?.train?.lineName ?? ''"/>
+                    <LineIndicator :product-name="state.status?.train?.category"
+                                   :number="state.status?.train?.lineName ?? ''"/>
                     <span class="ms-1" v-show="nextStation">next: {{ nextStation?.name }}</span>
                 </p>
                 <p class="mb-0">{{ state.status?.train?.destination?.name }} <small
@@ -113,7 +114,10 @@ export default defineComponent({
     position: fixed;
     bottom: 30px;
     left: 50%;
-    width: 400px;
-    margin-left: -200px;
+    width: 100%;
+    max-width: 100%;
+    margin-left: -50%;
+    padding-right: calc(var(--mdb-gutter-x) * 0.5);
+    padding-left: calc(var(--mdb-gutter-x) * 0.5);
 }
 </style>
diff --git a/resources/vue/helpers/DateRange.ts b/resources/vue/helpers/DateRange.ts
new file mode 100644
index 000000000..4b9c51711
--- /dev/null
+++ b/resources/vue/helpers/DateRange.ts
@@ -0,0 +1,45 @@
+import {DateTime, DateTimeFormatOptions} from "luxon";
+import {DateTimeOptions, LocaleOptions} from "luxon/src/datetime";
+import {Dtm} from "./DateTime";
+
+export class DtmRange {
+    dateTimeStart: Dtm;
+    dateTimeEnd: Dtm;
+    isSameDay: boolean = false;
+
+    constructor(start: Dtm, end: Dtm) {
+        this.dateTimeStart = start;
+        this.dateTimeEnd = end;
+    }
+
+    static fromISO(start: string, end: string, opts?: DateTimeOptions): DtmRange {
+        const startDtm: Dtm = new Dtm(start, opts);
+        const endDtm: Dtm = new Dtm(end, opts);
+        const startDate: string = start.substring(0, 10);
+
+        const range = new DtmRange(startDtm, endDtm);
+        range.isSameDay = end.startsWith(startDate);
+
+        return range;
+    }
+
+    toLocaleDateString(
+        formatOpts?: DateTimeFormatOptions,
+        opts?: LocaleOptions,
+    ): string {
+        if (this.isSameDay) {
+            return this.dateTimeStart.toLocaleString(formatOpts, opts);
+        }
+
+        return `${this.dateTimeStart.toLocaleString(formatOpts, opts)} - ${this.dateTimeEnd.toLocaleString(formatOpts, opts)}`;
+    }
+
+    toLocaleDateTimeString(
+        formatOpts?: DateTimeFormatOptions,
+        opts?: LocaleOptions,
+    ): string {
+        formatOpts = formatOpts || DateTime.DATETIME_FULL;
+
+        return `${this.dateTimeStart.toLocaleString(formatOpts, opts)} - ${this.dateTimeEnd.toLocaleString(formatOpts, opts)}`;
+    }
+}
diff --git a/resources/vue/helpers/DateTime.ts b/resources/vue/helpers/DateTime.ts
new file mode 100644
index 000000000..445a215d5
--- /dev/null
+++ b/resources/vue/helpers/DateTime.ts
@@ -0,0 +1,41 @@
+import {DateTime, DateTimeFormatOptions} from "luxon";
+import {DateTimeOptions, LocaleOptions} from "luxon/src/datetime";
+import {getActiveLanguage} from "laravel-vue-i18n";
+
+export class Dtm {
+    dateTime: DateTime;
+
+    constructor(date: string, opts?: DateTimeOptions) {
+        const defaultOpts: DateTimeOptions = {
+            locale: this.getLocale(),
+        }
+        opts = {...defaultOpts, ...opts};
+
+        this.dateTime = DateTime.fromISO(date, opts);
+    }
+
+    private getLocale(): string {
+        let locale: string = getActiveLanguage();
+
+        if (locale.startsWith('de')) {
+            return 'de';
+        }
+
+        if (locale === '') {
+            return 'en';
+        }
+
+        return locale;
+    }
+
+    static fromISO(date: string, opts?: DateTimeOptions): Dtm {
+        return new Dtm(date, opts);
+    }
+
+    toLocaleString(
+        formatOpts?: DateTimeFormatOptions,
+        opts?: LocaleOptions,
+    ): string {
+        return this.dateTime.toLocaleString(formatOpts, opts);
+    }
+}
diff --git a/routes/api.php b/routes/api.php
index a5913050a..961ca5e62 100644
--- a/routes/api.php
+++ b/routes/api.php
@@ -30,6 +30,7 @@
 use App\Http\Controllers\API\v1\TokenController;
 use App\Http\Controllers\API\v1\TransportController;
 use App\Http\Controllers\API\v1\TripController;
+use App\Http\Controllers\API\v1\TrustedUserController;
 use App\Http\Controllers\API\v1\UserController;
 use App\Http\Controllers\API\v1\WebhookController;
 use App\Http\Controllers\API\v1\YearInReviewController;
@@ -172,6 +173,7 @@
         Route::apiResource('station', StationController::class);                                        // currently admin/backend only
         Route::put('station/{oldStationId}/merge/{newStationId}', [StationController::class, 'merge']); // currently admin/backend only
 
+        Route::apiResource('user.trusted', TrustedUserController::class)->only(['index', 'store', 'destroy']);
         Route::apiResource('report', ReportController::class);
         Route::apiResource('operators', OperatorController::class)->only(['index']);
     });
diff --git a/storage/api-docs/api-docs.json b/storage/api-docs/api-docs.json
index ec495b9a2..432e21d3a 100644
--- a/storage/api-docs/api-docs.json
+++ b/storage/api-docs/api-docs.json
@@ -1514,6 +1514,11 @@
                                     "mapProvider": {
                                         "type": "string",
                                         "nullable": true
+                                    },
+                                    "friendCheckin": {
+                                        "type": "string",
+                                        "example": "forbidden",
+                                        "nullable": true
                                     }
                                 },
                                 "type": "object"
@@ -3447,8 +3452,8 @@
                 "tags": [
                     "Checkin"
                 ],
-                "summary": "Create a checkin",
-                "operationId": "createTrainCheckin",
+                "summary": "Check in to a trip.",
+                "operationId": "createCheckin",
                 "requestBody": {
                     "required": true,
                     "content": {
@@ -3473,11 +3478,21 @@
                     "400": {
                         "description": "Bad request"
                     },
-                    "409": {
-                        "description": "Checkin collision"
-                    },
                     "401": {
                         "description": "Unauthorized"
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/CheckinForbiddenWithUsersResponse"
+                                }
+                            }
+                        }
+                    },
+                    "409": {
+                        "description": "Checkin collision"
                     }
                 },
                 "security": [
@@ -3646,6 +3661,154 @@
                 ]
             }
         },
+        "/user/{user}/trusted": {
+            "get": {
+                "tags": [
+                    "User"
+                ],
+                "summary": "Get all trusted users for a user",
+                "description": "Get all trusted users for the current user or a specific user (admin only).",
+                "operationId": "trustedUserIndex",
+                "parameters": [
+                    {
+                        "name": "user",
+                        "in": "path",
+                        "description": "ID of the user (or string 'self' for current user)",
+                        "required": true,
+                        "schema": {
+                            "type": "string"
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "List of trusted users"
+                    },
+                    "401": {
+                        "description": "Unauthorized"
+                    },
+                    "403": {
+                        "description": "Forbidden"
+                    },
+                    "404": {
+                        "description": "User not found"
+                    },
+                    "500": {
+                        "description": "Internal Server Error"
+                    }
+                }
+            },
+            "post": {
+                "tags": [
+                    "User"
+                ],
+                "summary": "Add a user to the trusted users for a user",
+                "description": "Add a user to the trusted users for the current user or a specific user (admin only).",
+                "operationId": "trustedUserStore",
+                "parameters": [
+                    {
+                        "name": "user",
+                        "in": "path",
+                        "description": "ID of the user (or string 'self' for current user) who want's to trust.",
+                        "required": true,
+                        "schema": {
+                            "type": "string"
+                        }
+                    }
+                ],
+                "requestBody": {
+                    "required": true,
+                    "content": {
+                        "application/json": {
+                            "schema": {
+                                "required": [
+                                    "user_id"
+                                ],
+                                "properties": {
+                                    "userId": {
+                                        "type": "integer",
+                                        "example": "1"
+                                    },
+                                    "expiresAt": {
+                                        "type": "string",
+                                        "format": "date-time",
+                                        "example": "2024-07-28T00:00:00Z"
+                                    }
+                                },
+                                "type": "object"
+                            }
+                        }
+                    }
+                },
+                "responses": {
+                    "201": {
+                        "description": "User added to trusted users"
+                    },
+                    "400": {
+                        "description": "Bad Request"
+                    },
+                    "401": {
+                        "description": "Unauthorized"
+                    },
+                    "403": {
+                        "description": "Forbidden"
+                    },
+                    "404": {
+                        "description": "User not found"
+                    },
+                    "500": {
+                        "description": "Internal Server Error"
+                    }
+                }
+            }
+        },
+        "/user/{user}/trusted/{trustedId}": {
+            "delete": {
+                "tags": [
+                    "User"
+                ],
+                "summary": "Remove a user from the trusted users for a user",
+                "description": "Remove a user from the trusted users for the current user or a specific user (admin only).",
+                "operationId": "trustedUserDestroy",
+                "parameters": [
+                    {
+                        "name": "user",
+                        "in": "path",
+                        "description": "ID of the user (or string 'self' for current user)",
+                        "required": true,
+                        "schema": {
+                            "type": "string"
+                        }
+                    },
+                    {
+                        "name": "trusted",
+                        "in": "path",
+                        "description": "ID of the trusted user",
+                        "required": true,
+                        "schema": {
+                            "type": "integer"
+                        }
+                    }
+                ],
+                "responses": {
+                    "204": {
+                        "description": "User removed from trusted users"
+                    },
+                    "401": {
+                        "description": "Unauthorized"
+                    },
+                    "403": {
+                        "description": "Forbidden"
+                    },
+                    "404": {
+                        "description": "User not found"
+                    },
+                    "500": {
+                        "description": "Internal Server Error"
+                    }
+                }
+            }
+        },
         "/settings/account": {
             "delete": {
                 "tags": [
@@ -4569,6 +4732,16 @@
                 ],
                 "example": "suburban"
             },
+            "FriendCheckinSetting": {
+                "title": "FriendCheckinSetting",
+                "type": "string",
+                "enum": [
+                    "forbidden",
+                    "friends",
+                    "list"
+                ],
+                "example": "forbidden"
+            },
             "CheckinSuccessResource": {
                 "title": "CheckinResponse",
                 "properties": {
@@ -5039,6 +5212,20 @@
                 },
                 "type": "object"
             },
+            "TrustedUserResource": {
+                "title": "TrustedUser",
+                "properties": {
+                    "user": {
+                        "$ref": "#/components/schemas/LightUserResource"
+                    },
+                    "expiresAt": {
+                        "type": "string",
+                        "format": "date-time",
+                        "example": "2024-07-28T00:00:00Z"
+                    }
+                },
+                "type": "object"
+            },
             "UserAuthResource": {
                 "title": "UserAuth",
                 "properties": {
@@ -5138,8 +5325,6 @@
                 "description": "Fields for creating a train checkin",
                 "properties": {
                     "body": {
-                        "title": "body",
-                        "description": "Text that should be added to the post",
                         "type": "string",
                         "maxLength": 280,
                         "example": "Meine erste Fahrt nach Knuffingen!",
@@ -5152,76 +5337,81 @@
                         "$ref": "#/components/schemas/StatusVisibility"
                     },
                     "eventId": {
-                        "title": "eventId",
                         "description": "Id of an event the status should be connected to",
                         "type": "integer",
+                        "example": "1",
                         "nullable": true
                     },
                     "toot": {
-                        "title": "toot",
                         "description": "Should this status be posted to mastodon?",
                         "type": "boolean",
                         "example": "false",
                         "nullable": true
                     },
                     "chainPost": {
-                        "title": "chainPost",
                         "description": "Should this status be posted to mastodon as a chained post?",
                         "type": "boolean",
                         "example": "false",
                         "nullable": true
                     },
                     "ibnr": {
-                        "title": "ibnr",
-                        "description": "If true, the `start` and `destination` properties can be supplied as an ibnr. Otherwise they\n     *     should be given as the Träwelling-ID. Default behavior is `false`.",
+                        "description": "If true, the `start` and `destination` properties can be supplied as an ibnr. Otherwise they should be given as the Träwelling-ID. Default behavior is `false`.",
                         "type": "boolean",
                         "example": "true",
                         "nullable": true
                     },
                     "tripId": {
-                        "title": "tripId",
-                        "description": "The HAFAS tripId for the to be checked in train",
-                        "example": "1|323306|1|80|17072022"
+                        "description": "The tripId for the to be checked in train",
+                        "type": "string",
+                        "example": "b37ff515-22e1-463c-94de-3ad7964b5cb8",
+                        "nullable": true
                     },
                     "lineName": {
-                        "title": "lineName",
                         "description": "The line name for the to be checked in train",
-                        "example": "S 4"
+                        "type": "string",
+                        "example": "S 4",
+                        "nullable": true
                     },
                     "start": {
-                        "title": "start",
                         "description": "The Station-ID of the starting point (see `ibnr`)",
                         "type": "integer",
                         "example": "8000191"
                     },
                     "destination": {
-                        "title": "destination",
-                        "description": "The Station-ID of the destination (see `ibnr`)",
+                        "description": "The Station-ID of the destination point (see `ibnr`)",
                         "type": "integer",
-                        "example": "8079045"
+                        "example": "8000192"
                     },
                     "departure": {
-                        "title": "departure",
                         "description": "Timestamp of the departure",
+                        "type": "string",
+                        "format": "date-time",
                         "example": "2022-12-19T20:41:00+01:00"
                     },
                     "arrival": {
-                        "title": "arrival",
                         "description": "Timestamp of the arrival",
+                        "type": "string",
+                        "format": "date-time",
                         "example": "2022-12-19T20:42:00+01:00"
                     },
                     "force": {
-                        "title": "force",
-                        "description": "If true, the checkin will be created, even if a colliding checkin exists. No points will be\n     *     awarded.",
+                        "description": "If true, the checkin will be created, even if a colliding checkin exists. No points will be awarded.",
                         "type": "boolean",
                         "example": "false",
                         "nullable": true
+                    },
+                    "with": {
+                        "description": "If set, the checkin will be created for all given users as well. The user creating the checkin must be allowed to checkin for the other users. Max. 10 users.",
+                        "type": "array",
+                        "items": {
+                            "type": "integer",
+                            "example": "1"
+                        },
+                        "example": "[1, 2]",
+                        "nullable": true
                     }
                 },
-                "type": "object",
-                "xml": {
-                    "name": "CheckinRequestBody"
-                }
+                "type": "object"
             },
             "EventSuggestion": {
                 "title": "EventSuggestion",
@@ -5576,6 +5766,28 @@
                     "name": "Polyline"
                 }
             },
+            "CheckinForbiddenWithUsersResponse": {
+                "title": "CheckinForbiddenWithUsersResponse",
+                "properties": {
+                    "message": {
+                        "description": "example: {\"message\":\"You are not allowed to check in the following users: 1\",\"meta\":{\"invalidUsers\":[1]}}",
+                        "example": "You are not allowed to check in the following users: 1,2"
+                    },
+                    "meta": {
+                        "properties": {
+                            "invalidUsers": {
+                                "type": "array",
+                                "items": {
+                                    "type": "integer",
+                                    "example": "1"
+                                }
+                            }
+                        },
+                        "type": "object"
+                    }
+                },
+                "type": "object"
+            },
             "StatusTag": {
                 "title": "StatusTag",
                 "description": "StatusTag model",
diff --git a/tests/ApiTestCase.php b/tests/ApiTestCase.php
index 65671d6dd..463c4d2a0 100644
--- a/tests/ApiTestCase.php
+++ b/tests/ApiTestCase.php
@@ -3,7 +3,6 @@
 namespace Tests;
 
 use App\Models\User;
-use App\Providers\AuthServiceProvider;
 use Illuminate\Testing\TestResponse;
 use Laravel\Passport\Passport;
 
@@ -17,8 +16,11 @@ public function setUp(): void {
         $this->artisan('passport:keys', ['--no-interaction' => true]);
     }
 
-    protected function actAsApiUserWithAllScopes(): void {
-        Passport::actingAs(User::factory()->create(), ['*']);
+    protected function actAsApiUserWithAllScopes(User $user = null): void {
+        if ($user === null) {
+            $user = User::factory()->create();
+        }
+        Passport::actingAs($user, ['*']);
     }
 
     protected function assertUserResource(TestResponse $response): void {
diff --git a/tests/Feature/APIv1/FriendCheckinTest.php b/tests/Feature/APIv1/FriendCheckinTest.php
new file mode 100644
index 000000000..e2eaccede
--- /dev/null
+++ b/tests/Feature/APIv1/FriendCheckinTest.php
@@ -0,0 +1,148 @@
+<?php
+
+namespace Tests\Feature\APIv1;
+
+use App\Enum\User\FriendCheckinSetting;
+use App\Http\Controllers\Backend\User\FollowController;
+use App\Models\Follow;
+use App\Models\Trip;
+use App\Models\User;
+use App\Notifications\YouHaveBeenCheckedIn;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Gate;
+use Tests\ApiTestCase;
+
+class FriendCheckinTest extends ApiTestCase
+{
+
+    use RefreshDatabase;
+
+    public function testUserCanCheckinThemself(): void {
+        // a little bit useless, but a user can always check in themselves somehow ⊂(◉‿◉)つ
+        $user = User::factory()->create();
+        $this->assertTrue(Gate::forUser($user)->allows('checkin', $user));
+    }
+
+    public function testUserCanForbidFriendCheckins(): void {
+        $userToCheckin = User::factory(['friend_checkin' => FriendCheckinSetting::FORBIDDEN->value])->create();
+        $user          = User::factory()->create();
+        $this->assertFalse(Gate::forUser($user)->allows('checkin', $userToCheckin));
+    }
+
+    public function testUserCanAllowCheckinsForFriends(): void {
+        $userToCheckin = User::factory(['friend_checkin' => FriendCheckinSetting::FRIENDS->value])->create();
+        $user          = User::factory()->create();
+
+        $this->assertFalse(Gate::forUser($user->refresh())->allows('checkin', $userToCheckin->refresh()));
+
+        // Create a follow relationship between the two users (following each other = friends)
+        FollowController::createOrRequestFollow($user, $userToCheckin);
+        FollowController::createOrRequestFollow($userToCheckin, $user);
+
+        $this->assertTrue(Gate::forUser($user->refresh())->allows('checkin', $userToCheckin->refresh()));
+
+        // check that there are currently no checkins
+        $this->assertDatabaseCount('train_checkins', 0);
+
+        // check in both users
+        $trip = Trip::factory()->create();
+
+        $this->actAsApiUserWithAllScopes($user);
+        $response = $this->postJson(
+            uri:  '/api/v1/trains/checkin',
+            data: [
+                      'tripId'      => $trip->trip_id,
+                      'lineName'    => $trip->linename,
+                      'start'       => $trip->originStation->id,
+                      'departure'   => $trip->departure,
+                      'destination' => $trip->destinationStation->id,
+                      'arrival'     => $trip->arrival,
+                      'with'        => [
+                          $userToCheckin->id
+                      ]
+                  ],
+        );
+        $response->assertCreated();
+
+        $this->assertDatabaseHas('train_checkins', ['user_id' => $user->id, 'trip_id' => $trip->trip_id]);
+        $this->assertDatabaseHas('train_checkins', ['user_id' => $userToCheckin->id, 'trip_id' => $trip->trip_id]);
+
+        $notification = $userToCheckin->refresh()->notifications->where('type', YouHaveBeenCheckedIn::class)->last();
+        $this->assertStringContainsString($user->username, YouHaveBeenCheckedIn::getLead($notification->data));
+        $this->assertStringContainsString($trip->originStation->name, YouHaveBeenCheckedIn::getNotice($notification->data));
+        $this->assertStringContainsString($userToCheckin->statuses->last()->id, YouHaveBeenCheckedIn::getLink($notification->data));
+    }
+
+    public function testUserCanAllowCheckinsForTrustedUsers(): void {
+        $userToCheckin = User::factory(['friend_checkin' => FriendCheckinSetting::LIST->value])->create();
+        $user          = User::factory()->create();
+
+        $this->assertFalse(Gate::forUser($user->fresh())->allows('checkin', $userToCheckin->fresh()));
+
+        // Create a trusted relationship between the two users
+        $this->actAsApiUserWithAllScopes($userToCheckin);
+        $response = $this->postJson(
+            uri:  "/api/v1/user/{$userToCheckin->id}/trusted",
+            data: ['userId' => $user->id]
+        );
+        $response->assertCreated();
+
+        $this->assertTrue(Gate::forUser($user->fresh())->allows('checkin', $userToCheckin->fresh()));
+    }
+
+    public function testUserCannotCheckinMoreThen10Users(): void {
+        $usersToCheckin = User::factory()->count(11)->create();
+        $user           = User::factory()->create();
+
+        $trip = Trip::factory()->create();
+
+        $this->actAsApiUserWithAllScopes($user);
+        $response = $this->postJson(
+            uri:  '/api/v1/trains/checkin',
+            data: [
+                      'tripId'      => $trip->trip_id,
+                      'lineName'    => $trip->linename,
+                      'start'       => $trip->originStation->id,
+                      'departure'   => $trip->departure,
+                      'destination' => $trip->destinationStation->id,
+                      'arrival'     => $trip->arrival,
+                      'with'        => $usersToCheckin->pluck('id')->toArray()
+                  ],
+        );
+        $response->assertStatus(422);
+        $response->assertJsonValidationErrors('with');
+    }
+
+    public function testErrorResponseShouldContainForbiddenUsers(): void {
+        $forbiddenUser = User::factory()->create(['friend_checkin' => FriendCheckinSetting::FORBIDDEN->value]);
+        $allowedUser   = User::factory()->create(['friend_checkin' => FriendCheckinSetting::FRIENDS->value]);
+        $user          = User::factory()->create();
+        $this->actAsApiUserWithAllScopes($user);
+
+        Follow::create(['user_id' => $user->id, 'follow_id' => $allowedUser->id]);
+        Follow::create(['user_id' => $allowedUser->id, 'follow_id' => $user->id]);
+
+        $trip = Trip::factory()->create();
+
+        $response = $this->postJson(
+            uri:  '/api/v1/trains/checkin',
+            data: [
+                      'tripId'      => $trip->trip_id,
+                      'lineName'    => $trip->linename,
+                      'start'       => $trip->originStation->id,
+                      'departure'   => $trip->departure,
+                      'destination' => $trip->destinationStation->id,
+                      'arrival'     => $trip->arrival,
+                      'with'        => [
+                          $forbiddenUser->id,
+                          $allowedUser->id
+                      ]
+                  ],
+        );
+        $response->assertStatus(403);
+        $response->assertJsonStructure(['message', 'meta' => ['invalidUsers']]);
+        $this->assertContains($forbiddenUser->id, $response->json('meta.invalidUsers'));
+        $this->assertNotContains($allowedUser->id, $response->json('meta.invalidUsers'));
+    }
+}
+
diff --git a/tests/Feature/APIv1/TrustedUserTest.php b/tests/Feature/APIv1/TrustedUserTest.php
new file mode 100644
index 000000000..899021a7f
--- /dev/null
+++ b/tests/Feature/APIv1/TrustedUserTest.php
@@ -0,0 +1,122 @@
+<?php
+
+namespace Tests\Feature\APIv1;
+
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\ApiTestCase;
+
+class TrustedUserTest extends ApiTestCase
+{
+
+    use RefreshDatabase;
+
+    public function testListPagination(): void {
+        $user        = User::factory()->create();
+        $trustedUser = User::factory()->count(12)->create();
+        $this->actAsApiUserWithAllScopes($user);
+
+        foreach ($trustedUser as $userToTrust) {
+            $response = $this->postJson("/api/v1/user/self/trusted", ['userId' => $userToTrust->id]);
+            $response->assertCreated();
+        }
+
+        // list trusted users
+        $response = $this->getJson("/api/v1/user/self/trusted");
+        $response->assertOk();
+        $response->assertJsonCount(10, 'data');
+        $response->assertJsonStructure([
+                                           'data',
+                                           'links' => ['first', 'last', 'prev', 'next'],
+                                           'meta'  => ['path', 'per_page', 'next_cursor', 'prev_cursor'],
+                                       ]);
+
+        //try next cursor
+        $nextCursorResponse = $this->getJson($response->json('links.next'));
+        $nextCursorResponse->assertOk();
+
+        $nextCursorResponse->dump();
+        //TODO: why isn't the cursor working? Every request is showing from the beginning.
+    }
+
+    public function testStoreAndDeleteTrustedUserForYourself(): void {
+        $user        = User::factory()->create();
+        $trustedUser = User::factory()->create();
+        $this->actAsApiUserWithAllScopes($user);
+
+        // trust user
+        $response = $this->postJson("/api/v1/user/{$user->id}/trusted", [
+            'userId'    => $trustedUser->id,
+            'expiresAt' => now()->addDay()->toIso8601String(),
+        ]);
+        $response->assertCreated();
+        $this->assertDatabaseHas('trusted_users', ['user_id' => $user->id, 'trusted_id' => $trustedUser->id]);
+
+        // list trusted users
+        $response = $this->getJson("/api/v1/user/{$user->id}/trusted");
+        $response->assertOk();
+        $response->assertJsonCount(1, 'data');
+        $response->assertJsonFragment(['id' => $trustedUser->id]);
+
+        // test, that the cleanup script does not delete the trusted user
+        $this->assertDatabaseCount('trusted_users', 1);
+        $this->assertEquals(0, $this->artisan('app:clean-db:trusted-user'));
+        $this->assertDatabaseCount('trusted_users', 1);
+
+        $this->travel(2)->days();
+
+        // should not list expired trusted users, even if in database.
+        $response = $this->getJson("/api/v1/user/{$user->id}/trusted");
+        $response->assertOk();
+        $response->assertJsonCount(0, 'data');
+        $response->assertJsonMissing(['id' => $trustedUser->id]);
+
+        // now the cleanup script should delete the trusted user
+        $this->assertDatabaseCount('trusted_users', 1);
+        $this->assertEquals(0, $this->artisan('app:clean-db:trusted-user'));
+        $this->assertDatabaseCount('trusted_users', 0);
+    }
+
+    public function testStoreAndDeleteTrustedUserForOtherUsersAsNonAdmin(): void {
+        $user        = User::factory()->create();
+        $truster     = User::factory()->create();
+        $trustedUser = User::factory()->create();
+        $this->actAsApiUserWithAllScopes($user);
+
+        // trust user
+        $response = $this->postJson("/api/v1/user/{$truster->id}/trusted", ['userId' => $trustedUser->id]);
+        $response->assertForbidden();
+
+        // list trusted users
+        $response = $this->getJson("/api/v1/user/{$truster->id}/trusted");
+        $response->assertForbidden();
+
+        // untrust user
+        $response = $this->deleteJson("/api/v1/user/{$truster->id}/trusted/{$trustedUser->id}");
+        $response->assertForbidden();
+    }
+
+    public function testStoreAndDeleteTrustedUserForOtherUsersAsAdmin(): void {
+        $user        = User::factory()->create()->assignRole('admin');
+        $truster     = User::factory()->create();
+        $trustedUser = User::factory()->create();
+        $this->actAsApiUserWithAllScopes($user);
+
+        // trust user
+        $response = $this->postJson("/api/v1/user/{$truster->id}/trusted", ['userId' => $trustedUser->id]);
+        $response->assertCreated();
+        $this->assertDatabaseHas('trusted_users', ['user_id' => $truster->id, 'trusted_id' => $trustedUser->id]);
+
+        // list trusted users
+        $response = $this->getJson("/api/v1/user/{$truster->id}/trusted");
+        $response->assertOk();
+        $response->assertJsonCount(1, 'data');
+        $response->assertJsonFragment(['id' => $trustedUser->id]);
+
+        // untrust user
+        $response = $this->deleteJson("/api/v1/user/{$truster->id}/trusted/{$trustedUser->id}");
+        $response->assertNoContent();
+        $this->assertDatabaseMissing('trusted_users', ['user_id' => $truster->id, 'trusted_id' => $trustedUser->id]);
+    }
+}
+
diff --git a/tests/Feature/Profile/UserModelRelationshipTest.php b/tests/Feature/Profile/UserModelRelationshipTest.php
new file mode 100644
index 000000000..d2e5ac1d9
--- /dev/null
+++ b/tests/Feature/Profile/UserModelRelationshipTest.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace Tests\Feature\Profile;
+
+use App\Http\Controllers\Backend\User\FollowController;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\FeatureTestCase;
+
+class UserModelRelationshipTest extends FeatureTestCase
+{
+    use RefreshDatabase;
+
+    public function testFollowersRelationship(): void {
+        $user     = User::factory()->create();
+        $follower = User::factory()->create();
+        FollowController::createOrRequestFollow($follower, $user);
+
+        $user->refresh();
+
+        $this->assertCount(1, $user->userFollowers);
+        $this->assertEquals($follower->id, $user->userFollowers->first()->id);
+    }
+
+    public function testFollowingRelationship(): void {
+        $user      = User::factory()->create();
+        $following = User::factory()->create();
+        FollowController::createOrRequestFollow($user, $following);
+
+        $user->refresh();
+
+        $this->assertCount(1, $user->userFollowings);
+        $this->assertEquals($following->id, $user->userFollowings->first()->id);
+    }
+}
diff --git a/tests/Unit/Services/ReportServiceTest.php b/tests/Unit/Services/ReportServiceTest.php
index 0fea1a859..583854999 100644
--- a/tests/Unit/Services/ReportServiceTest.php
+++ b/tests/Unit/Services/ReportServiceTest.php
@@ -12,7 +12,7 @@ class ReportServiceTest extends UnitTestCase
 {
 
     /**
-     * @dataProvider testCheckStringProvider
+     * @dataProvider checkStringProvider
      */
     public function testCheckString(array $expected, string $haystack): void {
         $reportService = new ReportService();
@@ -26,7 +26,7 @@ public function testCheckString(array $expected, string $haystack): void {
 
 
     /**
-     * @dataProvider testCheckStringProvider
+     * @dataProvider checkStringProvider
      */
     public function testCheckAndReport(array $expected, string $haystack): void {
         $repository = $this->mock(ReportRepository::class);
@@ -50,7 +50,7 @@ public function testCheckAndReport(array $expected, string $haystack): void {
         $reportService->checkAndReport($haystack, ReportableSubject::TRIP, 1);
     }
 
-    public static function testCheckStringProvider(): array {
+    public static function checkStringProvider(): array {
         return [
             'match first word'                                   => [
                 ['auto'],