I don't know if they're really lesser known, but PictureMushroom, LeafSnap & AllTrails, would all be so neat with nostr integration. Maybe there's some lesser known versions that would be willing? Also Scout To Hunt... they're very obviously bitcoiners lol 

 Great suggestions! 

 alltrails can get fucked with their subscription

just integrate zaps with OSM or Organic Maps.  Add a add hiking trail fxn