An Android app for tagging GPS coordinates in the field. Designed for use on a tractor or while walking an orchard — large, high-contrast buttons that are easy to tap with gloves on.
- One-tap GPS tagging — six large buttons each save your current location with a label
- Live GPS status — color-coded accuracy indicator (green ≤ 5 m, amber ≤ 15 m, red > 15 m)
- Map view — all saved points displayed on a map with a color-coded legend; switch between street map (OpenStreetMap) and satellite imagery (ESRI World Imagery) via the overflow menu
- My Location — tap the location button on the map to center on your current GPS position
- Delete points — tap any marker to delete it individually, or use "Select Area" to drag a rectangle and delete all points within it
- Filter by tag — use "Filter Tags" in the map menu to show only selected tag types; filters by tag name so reassigned slots don't cause collisions
- Custom labels — rename any button to suit your operation (changes persist across sessions)
- In-app updates — check for new versions from the overflow menu; downloads and installs directly
- CSV export — share your tagged points via email, Drive, or any other app
- Screen stays on — display never sleeps while the app is open
- Haptic feedback — short vibration confirms every saved point without looking at the screen
- Offline map tiles — download street map or satellite tiles for any area so the map works without cell service
- External USB GPS support — plug in any NMEA 0183 receiver (u-blox, GlobalSat BU-353, BadElf, Garmin GLO, generic CDC/FTDI/CP210x/CH34x serial pucks) for survey-grade accuracy; toggle the source in ⋮ → Settings
- No account or API key required
| Button | Default label |
|---|---|
| 🟢 | Gopher |
| 🔴 | Blight |
| 🟠 | Blackberry |
| 🔵 | Broken Irrigation |
| 🟣 | Prune |
| 🟡 | End Tank |
All labels can be renamed via ⋮ → Edit Labels from the main screen.
Download the latest APK (v1.5.0)
On your Android device, open the downloaded file and follow the prompts. If prompted, enable Install from unknown sources in Settings → Security.
- Android 8.0 (Oreo) or newer (API 26+)
- GPS / location permission
- Internet connection for map tiles (map markers and saved data work fully offline)
- Install Android Studio — download from developer.android.com/studio
- Clone the repository
git clone https://github.com/ctdenney/OrchardTracker.git
- Open the project — in Android Studio choose File → Open and select the
OrchardTrackerfolder - Let Gradle sync — Android Studio will download all dependencies automatically (requires an internet connection)
- Connect your phone — enable USB Debugging on the device:
- Go to Settings → About Phone and tap Build Number seven times to unlock Developer Options
- Go to Settings → Developer Options and enable USB Debugging
- Connect via USB and accept the prompt on the phone
- Run the app — press the green ▶ Run button in Android Studio
-
Install prerequisites
- JDK 17 or newer
- Android SDK (install via Android Studio or the standalone SDK tools)
- Set the
ANDROID_HOMEenvironment variable to your SDK path
-
Clone the repository
git clone https://github.com/ctdenney/OrchardTracker.git cd OrchardTracker -
Generate the Gradle wrapper (first time only)
gradle wrapper --gradle-version=8.4
-
Build a debug APK
./gradlew assembleDebug
The APK will be output to:
app/build/outputs/apk/debug/app-debug.apk -
Install on a connected device
./gradlew installDebug
Or copy the APK to your phone and open it (you may need to allow Install from unknown sources in your device settings).
| Permission | Why it's needed |
|---|---|
ACCESS_FINE_LOCATION |
Records precise GPS coordinates when a button is pressed |
ACCESS_COARSE_LOCATION |
Fallback if fine location is unavailable |
INTERNET |
Downloads map tiles from OpenStreetMap / ESRI |
VIBRATE |
Haptic confirmation when a point is saved |
- Open the app and wait for the GPS indicator to turn amber or green
- Tap any of the six tag buttons — the point is saved instantly with a timestamp
- A toast notification and short vibration confirm the save
- Tap View Map at the bottom of the main screen
- The map centers on all your recorded points
- Tap any marker to see its label, timestamp, and accuracy — tap Delete in that dialog to remove it
- Use the Legend overlay (bottom-left of the map) to see which color is which label
- Tap the location button (bottom-right of the map) to center on your current GPS position
- Tap ⋮ → Switch to Satellite to view ESRI World Imagery instead of the street map (tap again to switch back)
- Tap ⋮ → Filter Tags to show only selected tag types on the map
- Tap Select Area in the bottom bar — the button turns orange
- Drag a rectangle over the map to select the points you want to remove
- Confirm the deletion in the dialog that appears
- Tap Cancel at any time to exit selection mode without deleting
- Tap ⋮ (top-right overflow menu) → Edit Labels
- Type a new name for any button — leave blank to restore the default
- Tap Save Labels
- Tap View Map → ⋮ → Download Offline Map
- Select the tile source — Street Map (OSM) or Satellite (ESRI)
- Pan and zoom the map to the area you want to cache
- Adjust the Zoom range (8 = regional overview, 13 = individual fields, 18 = row-level detail)
- Check the tile / size estimate, then tap Download Area
- A progress bar tracks the download — the app can be used normally once it finishes
Tip: Zoom levels 13–17 cover most orchard work and typically download in under a minute on a good connection. Wider zoom ranges increase download size exponentially. Download both tile sources separately if you want to switch between them offline.
To free up storage, tap Clear Cache on the same screen.
- Tap View Map → Export CSV
- Choose a share target (email, Google Drive, etc.)
The CSV format is:
id,tag,latitude,longitude,altitude_m,accuracy_m,timestamp
| Component | Library |
|---|---|
| Language | Kotlin |
| Build | Gradle 8.4 / AGP 8.2 |
| UI | Material Components for Android |
| Database | Room (SQLite) |
| Location | Google Play Services — FusedLocationProviderClient |
| Maps | OSMDroid — OpenStreetMap street tiles + ESRI World Imagery satellite tiles (no API key) |
| Async | Kotlin Coroutines |
MIT