About this project

Trail Sense is an open-source Android application focused on wilderness navigation and survival assistance using a phone's built-in sensors. The app is designed to work entirely offline with no internet dependency. Key features include: Navigation Tools: Place beacons and navigate to them, follow paths, and retrace steps using a backtrack feature. A sighting compass and clinometer utilize the phone's camera and sensors for field measurements. Photo maps let users take or select a photo to use as a navigational reference. Weather and Astronomy: The app predicts weather based on local altitude and pressure history stored in app preferences over the last 48 hours. It also provides sunrise, sunset, and other astronomy event predictions with configurable alerts. Outdoor Utilities: A flashlight tool controls the phone's torch, and a water boil timer helps with camp tasks. The app includes a cloud scanner and QR code scanner using the camera. Offline Design: All location data, beacon coordinates, paths, and sensor readings remain on-device. The app stores data locally in SQLite and app preferences, clearing everything when storage is cleared or the app is deleted. Permissions required include fine and coarse location access, background location for sunset alerts, activity recognition for pedometer-based distance calculation, camera for the compass and scanners, and exact alarm scheduling for time-based notifications. The project welcomes contributions, translations via Weblate, and feature requests through GitHub discussions. It is available on F-Droid, Google Play, and via Obtainium. A companion survival guide is also published separately. Licensed under MIT. Official links: - User Guide: https://kylecorry.com/Trail-Sense/user-guide/ - Technical blog/research: https://kylecorry.com/research/categories/trail-sense/ - Feature roadmap and wiki: https://github.com/kylecorry31/Trail-Sense/wiki