Will Be usefull the chance to follow tracks during outdoor activity. Once you choose the track, and maybe waypoint, you have message (vibrations or vocale) if you are going out of track, or when you reach waypoint. In this way mytrail can really drive you as you are riding or running…
I also ask to have this feature.
Almost easy to develope and very useful.
I always keep screen off when unsused (battery saving) and may happen to step away from track. In my opinion, an audio notification will be the best solution.