OpenTracksApp/OpenTracks ? reverse-engineered prompt

Build me an Android app for tracking outdoor and fitness activities that works fully offline and respects privacy.

I want it to record GPS tracks, show basic stats while I’m moving, and let me pause and resume a recording. It should also support Bluetooth sensors for things like heart rate, cadence, speed, distance, and power, so I can use it for cycling, running, and indoor training too.

Please include voice announcements, the ability to drop markers during a workout, and attach photos to a track. After I finish, I want to export the activity as GPX, KML, or KMZ, and it would be great if it could auto export after each recording so I can sync it elsewhere.

Keep it simple, clean, and private, with no ads, no analytics, and no internet needed for normal use. If you need to check current docs or best practices for Android permissions or Bluetooth support, look them up online first.