Cell Recorder

Cell Recorder is an Android app that records cellular tower information (signal strength, Cell ID, RAT type, frequency bands) alongside GPS coordinates. Sessions can be exported as CSV or GeoJSON, and replayed on an interactive map.

Features

• Real-time cell tower logging — Records signal strength, Cell ID, RAT (4G/5G/etc.), and frequency bands using NetMonster Core
• GPS tracking — Logs location coordinates during recording sessions
• Background recording — Foreground service keeps recording active even when the app is in the background
• Session management — Name, view, and manage multiple recording sessions
• Export — Save sessions as CSV or GeoJSON
• Replay — Replay recorded sessions on an interactive OpenStreetMap view
• Crash logging — Built-in uncaught exception handler captures crash logs for easy bug reporting
• In-app issue reporting — Pre-filled GitHub issue template from the About screen

Screenshots

Screenshots

Home & Recording

Session List

Recording Screen

Live Info & Analytics

Live Cell Info	Global Statistics
Session Analytics

Video Demo

Cell record replay #1

Cell record replay #2

Permissions

Permission	Why it's needed
ACCESS_FINE_LOCATION	Record precise GPS coordinates alongside cell data
ACCESS_BACKGROUND_LOCATION	Continue recording location when the app is not in the foreground
READ_PHONE_STATE	Read cell tower information (signal strength, Cell ID, RAT, bands)
POST_NOTIFICATIONS	Show a persistent notification while recording is active
FOREGROUND_SERVICE	Run the recording service in the foreground
FOREGROUND_SERVICE_LOCATION	Declare the foreground service type for location tracking

Building

Debug

./gradlew assembleDebug

The debug APK will be at app/build/outputs/apk/debug/app-debug.apk.

Release

Release builds require signing environment variables:

export RELEASE_STORE_PASSWORD="your_keystore_password"
export RELEASE_KEY_ALIAS="your_key_alias"
export RELEASE_KEY_PASSWORD="your_key_password"
./gradlew assembleRelease

The signed release APK will be at app/build/outputs/apk/release/app-release.apk.

Note: Do not commit your keystore (*.jks) or hardcode signing passwords in build.gradle.kts.

Architecture

• UI: Jetpack Compose with Material 3
• Dependency Injection: Hilt
• Database: Room (for sessions and cell readings)
• Cell Info: NetMonster Core
• Maps: osmdroid (OpenStreetMap)
• Location: Google Play Services Location

Contributing

Contributions are welcome! Please open an issue to discuss changes before submitting a pull request.

License

Apache License 2.0