I track many things in Google Earth, and GE speaks KML natively, as do many GPS devices. I think KML is the de facto standard on this sort of stuff, tho you may have to check my math on that point.
KML is basically XML with some geographic data built in to the protocol.
I would therefore recommend considering whether it makes sense for your app to speak KML. My GPS watch tracks paths and points in KML, then it seamlessly uploads into GE. Not sure if this is the goal of your app or not. Just a suggestion to look into.