Onlink

Onlink is two coordinated Flutter apps — a GetX-based chat client and a separate admin console — reading and writing one shared Firestore backend. Rather than a generic messenger, the client is built around privacy features: message data is encrypted on the device before it is stored, and decrypted again on read.

Conversations also self-destruct on a timer, adjustable from 1 to 6 days per chat or group. Each message stores its own expiry timestamp (current time plus the chat's configured window), and the conversation list filters out any message whose expiry has passed at render time, so old messages actually disappear rather than just being hidden behind a setting. On top of that, the chat screen blocks screenshots and screen recording, and a 5-minute idle timer signs the user out automatically.

Starting a 1:1 chat goes through a request/approve flow — search a user by email or name, send a request, and the recipient has to accept before either side can message (chats carry a waiting/approved/rejected status). Group chats sit behind a matching admin-side workflow: the admin console's "Groups Requests" queue lets an admin review a new group's member list, add or remove members, and approve or reject it before it can be used.

The admin console itself is the operational side of the same product: create and manage user accounts, review the pending-groups queue, browse all groups, and — behind a Firebase re-authentication prompt that requires re-entering the admin's password — bulk-delete all chats or wipe all app data. Voice messages (in-app recording via the device mic, uploaded to Firebase Storage, played back with position/duration controls) and image messages round out the message types.