While using the Strava app, it would be great to be able to see other unknown Bluetooth (BLE) devices that may be nearby.
I have found many times riding in heavily wooded areas that either other mountain bike riders, hikers, or even myself, have been surprised or nearly hit by oncoming mountain bikers.
Wouldn't it be awesome if there could be an icon on the map that showed other unknown BLE devices and their relative strength? This BLE signal strength could be used to determine the distance away and if the device is getting closer. Perhaps play an audible tone that changes to indicate proximity?
With almost everyone carrying a device like a phone, watch, fitbit, etc., this idea/technology could be extremely helpful in minimizing, if not preventing, dangerous collisions on trails.