A disaster response communication app using Bluetooth Low Energy (BLE) mesh networking for offline peer-to-peer messaging when internet and cellular networks are unavailable.
Download the latest APK from Google Drive page.
Download the latest version of Gemma 3:1b.litertlm from Hugging Face page.
- Open the downloaded APK file on your Android device
- Grant installation permissions if prompted
- Open the app and allow Bluetooth permissions when requested
That's it! No internet or account required.
- Offline Communication: Works without internet or cellular service
- Automatic Mesh: Messages relay through nearby devices (up to 5 hops)
- Auto-Connect: Devices automatically discover and connect to each other
- No Setup Required: Just open the app - advertising and scanning start automatically
Send pre-defined emergency alerts with one tap:
- 🆘 HELP - Need assistance immediately
- 🏥 MEDICAL - Urgent medical help needed
- 🚨 TRAPPED - Cannot move, need rescue
- � FLOOD - Water rising, danger zone
- 🔥 FIRE - Active fire in area
⚠️ EVACUATE - Leave area immediately
- Broadcast messages to all connected devices
- View connection count and message history
- Messages automatically relay to extend range
- Real-time network status indicators
- 100% Local: All communication stays on-device
- No Servers: Direct device-to-device messaging
- No Tracking: No accounts, no data collection
- Anonymous: Device IDs are randomized
- Android 8.0+ (API level 26 or higher)
- Bluetooth 4.0+ with BLE support
- Location Permission: Required for BLE scanning on Android
- ~10 meters range per device connection
- Open the app - Advertising and scanning start automatically
- Wait for connections - Devices discover each other within ~10m
- Send messages - Tap quick emergency buttons or use global chat
- Messages relay - Connected devices forward messages automatically
- Mesh extends range - Reach devices up to 50m+ away through relay
- View connected device count
- Monitor total messages sent
- Check signal strength status
- See active connections
- Physical proximity required: Devices must be within Bluetooth range (~10m)
- Battery usage: Continuous BLE operation uses ~10-15% battery per hour
- Android only: Currently supports Android devices only
- Permissions: Must grant Bluetooth and Location permissions for full functionality
- Best for emergencies: Designed for disaster scenarios when normal networks fail
- Natural disasters: Earthquakes, hurricanes, floods
- Search and rescue: Coordinate rescue efforts in remote areas
- Emergency evacuation: Communicate during power/network outages
- Disaster response teams: Field coordination without infrastructure
- Community alerts: Warn neighbors of immediate dangers
- No internet connection required or used
- No user accounts or registration
- No data sent to external servers
- Device IDs are randomly generated
- Messages stored only on device
- Bluetooth connections are local only
- Technology: React Native + Expo
- BLE Stack: react-native-ble-plx
- Native Modules: Kotlin (Android)
- Message Format: GATT characteristics
- Network Topology: Mesh with automatic relay
- Max Hops: 5 (configurable)
MIT
Built for emergency preparedness and disaster response scenarios where traditional communication infrastructure may be unavailable.