In aviation, we use the following:
Speed= "knots" or nm/h (nautical miles per hour i.e "460 nm/h" or "460 kts")
length/distance= nm (nautical miles i.e. "50.1 nm")
Altitude = feet


Not sure on the two points. I'll let someone who uses GPS for land navigating/geocaching, etc. give you ideas on that one. I'm sure there are some standards but I can't recall what they are.


Awesome app by the way!