Toolbox

A privacy-respecting, offline-first Android utility app with 25+ tools across measurement, conversion, and everyday use. Built with Kotlin, Jetpack Compose, and Material 3.

Features

Measurement

- Bubble Level: circular and linear level with pitch/roll readout - Compass: compass rose with magnetic/true north toggle - Protractor: on-screen angle measurement - Sound Meter: live dB meter with min/avg/max stats - Ruler: full-width ruler with cm/in toggle and credit-card calibration - Light Meter: ambient lux sensor readout - Barometer: atmospheric pressure via pressure sensor - Altitude: elevation estimate from barometric pressure - Gyroscope: real-time angular velocity on all three axes - Humidity: relative humidity on supported hardware - Metal Detector: magnetic field strength as a proximity indicator - Speedometer: GPS-based speed with unit toggle - Vibrometer: vibration intensity from accelerometer - Spectrum Analyzer: real-time audio frequency spectrum via FFT

Conversion

- Unit Converter: 10+ categories including length, weight, temperature, and volume - Percentage Calculator: percent of, percent change, and reverse calculations - Tip Calculator: bill splitting with custom tip percentage - Number Base: convert between binary, octal, decimal, and hex

Everyday

- QR Scanner: scan barcodes and QR codes, generate QR codes from text - Counter: persistent multi-step counter with DataStore persistence - Stopwatch & Timer: stopwatch with laps, countdown timer with background notification - Random: dice rolls, coin flip, and random number generator - Color Picker: sample any colour from the camera feed - Magnifier: camera-based magnifier with zoom control - Mirror: front camera as a mirror - Heart Rate: estimate BPM via rear camera finger placement

Other

- Flashlight: torch with brightness control, SOS mode, and strobe - Pedometer: step counter using the hardware step sensor

Platform Features

- Quick Settings Tiles for Flashlight, Sound Meter, Bubble Level, and Timer - App Shortcuts to jump to frequently used tools - Favorites screen for pinning any tool - Share Measurements: export a measurement card image from any sensor tool - Dynamic theming with Material You on Android 12+ and static fallback on older devices - Full support for Android 14 predictive back gesture

Disclaimer

Toolbox is an independent project. It collects no analytics, no crash reports, and no ads. All sensor data stays on-device, and runtime permissions are requested only when the relevant tool is opened.

License

MIT