Anchor

Remote device location and control via SMS

A privacy-focused Android application that enables you to locate and control your lost or stolen device remotely via SMS commands. No internet required, no servers involved - just direct SMS communication between your devices.

Purpose

Anchor provides comprehensive remote control of your Android device through secure SMS commands, helping you recover lost or stolen devices:

• Device Location: Get precise GPS coordinates with Google Maps link
• Remote Ring: Make your device ring at maximum volume, even when silenced
• Device Status: Check battery level, charging status, and screen state
• Call Back: Make your device call you immediately
• Sound Control: Remotely change device sound mode (Normal/Vibrate/Silent)
• Service Check: Verify the tracking service is active

Use Cases

• Locate lost device using GPS coordinates
• Ring device to find it nearby
• Get device status when lost
• Make device call you back
• Control device remotely when stolen
• Track device location for recovery

The app operates completely offline using SMS, providing:

• No Internet Required: Works via cellular SMS
• No Data Collection: All operations are local
• Privacy-First: No servers, no tracking, no analytics
• Secure: Password protection and phone whitelist

Features

• 7 SMS Commands: Complete remote control of your device
• Password Protected: All commands require authentication
• Phone Whitelist: Restrict control to trusted contacts only
• Custom Prefix: Personalize your command trigger word
• Privacy-Focused: No internet permissions, all operations are local
• Modern Material Design 3 Interface: Clean, intuitive UI built with Jetpack Compose

Configuration

SMS Commands

The app supports 7 remote control commands:

Device Location:

• locate - Get GPS coordinates and Google Maps link

Device Control:

• ring - Play loud alarm at maximum volume
• info - Get battery level, charging status, screen state
• callme - Make device call you back immediately
• sound [mode] - Change sound mode (normal/vibrate/silent)

Service Management:

• ping - Check if Anchor service is running
• help - Get list of all available commands

Command Configuration

1. Open the app and navigate to Command Settings
2. Set your Command Prefix (default: PIN)
3. Create a strong Command Password
4. Save the configuration

Whitelist Setup (Recommended)

1. Navigate to Phone Whitelist
2. Enable whitelist protection
3. Add trusted phone numbers:
   • Import from contacts, or
   • Add manually
4. Only whitelisted numbers can control your device

Requirements

• Android 8.0 (Oreo, API 26) or higher
• Active SIM card with SMS capability
• GPS/Location services
• Phone call capability

Installation

1. Download the latest APK from the Releases page
2. Install on your Android device
3. Open the app and grant required permissions:
   • SMS (Read & Send)
   • Location (Precise & Background)
   • Phone (Make Calls)
   • Display Over Other Apps
4. Configure your command prefix and password
5. Set up phone number whitelist for security
6. Test with a ping command from trusted number

Project Structure

app/
├── src/main/java/com/supernova/anchor/
│   ├── MainActivity.kt                     # Main entry point
│   ├── SettingsActivity.kt                 # App settings
│   ├── PermissionsActivity.kt              # Permission management
│   ├── CommandSettingsActivity.kt          # Command configuration
│   ├── WhitelistActivity.kt                # Phone whitelist management
│   ├── AboutActivity.kt                    # App information
│   ├── receiver/
│   │   └── SmsReceiver.kt                  # SMS command receiver
│   ├── service/
│   │   └── OverlayDisplayService.kt        # Alert display service
│   └── utils/
│       ├── SmsCommandProcessor.kt          # Command processing logic
│       ├── LocationUtils.kt                # GPS location services
│       ├── WhitelistManager.kt             # Whitelist management
│       ├── PermissionManager.kt            # Permission handling
│       ├── AppSettings.kt                  # Settings storage
│       └── RingtonePlayer.kt               # Ring command handler
├── src/main/res/                           # Resources (layouts, strings, etc.)
└── build.gradle.kts                        # App build configuration

.github/workflows/                          # CI/CD pipelines
├── build.yml                               # Continuous Integration
└── release.yml                             # Release automation

gradle/
├── libs.versions.toml                      # Version catalog
└── wrapper/                                # Gradle wrapper

build.gradle.kts                            # Root build configuration
settings.gradle.kts                         # Project settings

Building from Source

# Clone the repository
git clone https://github.com/aunchagaonkar/anchor.git
cd anchor

# Build debug APK
./gradlew assembleDebug

# Build release APK
./gradlew assembleRelease

Security & Privacy

What We DON'T Do

• No internet access
• No data collection
• No analytics or tracking
• No third-party services
• No background data sync
• No user accounts

What We DO

• SMS-only communication
• Password protection
• Phone number whitelist
• Local data storage only
• Open source code
• Transparent operations

Security Best Practices

1. Use a strong, unique password (12+ characters)
2. Enable phone whitelist protection
3. Only add trusted contacts to whitelist
4. Regularly review whitelist entries
5. Keep the app updated
6. Never share your command password

TODO

• SMS command processing
• GPS location tracking
• Remote device ring
• Call back feature
• Sound mode control
• Password protection
• Phone whitelist
• Rate limiting for commands
• Geofencing alerts
• Multi-language support

Contributing

Contributions are welcome! Please follow these guidelines:

Getting Started

1. Fork the repository
2. Create a feature branch (git checkout -b feature/feature-name)
3. Make your changes following the project's code style
4. Test your changes thoroughly
5. Commit your changes (git commit -m 'Add feature-name')
6. Push to the branch (git push origin feature/feature-name)
7. Open a Pull Request

Code Style

• Follow Kotlin coding conventions
• Use meaningful variable and function names
• Add documentation for public APIs
• Maintain clean architecture principles
• Follow Material Design guidelines for UI changes

Testing

• Test on multiple Android versions (8.0+)
• Verify all SMS commands work correctly
• Test permission flows
• Validate security features
• Test on different devices/manufacturers

Reporting Issues

• Use the GitHub issue tracker
• Provide detailed reproduction steps
• Include device information and Android version
• Attach relevant logs when possible

LICENSE

This project is licensed under the GNU General Public License v3.0. See the LICENSE file for details.

Dependencies and Credits

Core Dependencies

• Jetpack Compose: Modern UI framework
• Material Design 3: UI components and theming
• Play Services Location: GPS location services
• Kotlin Coroutines: Asynchronous operations
• AndroidX Libraries: Core Android components

Permissions Used

• SMS: Receive and send command messages
• Location: Determine device position
• Phone: Make callback calls
• Display Over Other Apps: Show alerts

Special thanks to the Android development community and the maintainers of the open-source libraries used in this project.

Disclaimer

Important: This app is designed to help you locate and control YOUR OWN device if it's lost or stolen. It is NOT intended for:

• Surveillance or tracking others
• Covert monitoring
• Unauthorized access to devices

Using this app to track others without their knowledge may be illegal in your jurisdiction. Always comply with local laws and respect privacy rights.

Legal:

• Use only on devices you own or have permission to track
• Comply with local privacy and surveillance laws
• Disable before selling/transferring device