Hisn - App Lock & Privacy

Hisn (Arabic for "fortress") locks your apps behind a PIN or fingerprint so nobody can open them without your permission.

HOW IT WORKS
- Set a 4-8 digit PIN
- Choose which apps to protect
- When someone opens a protected app, Hisn shows the lock screen
- Unlock with your PIN or fingerprint

FEATURES

- PIN Lock: Set a 4-8 digit PIN to protect any app on your device
- Biometric Unlock: Use fingerprint or face recognition for quick access
- Intruder Detection: Automatically captures a front camera photo after 3 wrong PIN attempts
- Fake Crash Screen: Shows a realistic "App has stopped" dialog instead of the lock screen to fool intruders
- Notification Hiding: Shows only the app's name and a count, and keeps the message hidden until you unlock the app
- PIN Recovery (optional): Link an email so you can reset a forgotten PIN
- Stealth Mode: Hides Hisn from the app launcher so nobody knows it is installed
- Auto Re-Lock: Re-locks apps after the screen turns off, with configurable delay
- Grace Period: After unlocking, switch between apps without re-entering your PIN for a set time
- Hide from Recents: Removes Hisn from the recent apps list
- Dark Mode: System, Light, and Dark theme options
- Cooldown Protection: After 5 wrong PIN attempts, enforces a 30-second cooldown
- Tablet and Foldable Support: Adaptive layout with navigation rail on larger screens

WHY YOU WILL LIKE IT

- Lightweight and battery-friendly
- Clean, modern Material 3 design
- Simple to set up in under a minute

PRIVACY AND SECURITY

- Your PIN is stored as a SHA-256 hash and never saved in plain text
- Your protected apps, settings, and intruder photos stay on your device
- The recovery account is optional: if you link one, your email and password go to Google Firebase, and you can delete the account in Settings
- Privacy policy: https://privacy.saifullah.ai/Hisn

PERMISSIONS EXPLAINED

- Accessibility Service: Required to detect when a protected app is opened
- Camera: Used only for intruder detection (optional)
- Biometric: Used for fingerprint or face unlock (optional)
- Notification Listener: Used to hide what notifications from protected apps say (optional)
- Notifications: Used to show Hisn's private alert (optional)
- Device Administrator: Used for uninstall protection (optional)
- Internet: Used only for the optional recovery account

SUPPORT

Email: www.saifullah.ai@gmail.com
Website: https://saifullah.ai