Worth looking up "APRS101" -
http://www.aprs.org/doc/APRS101.PDF - and reading it cover to cover. The position format you're looking for is on p23. If you count compressed, uncompressed, objects, Items, NMEA, MIC-E, with/without timestamps, There are also probably a dozen other position formats to choose from. You'll probably be screaming "WHY OH WHY" by the end of it, but you'll
understand the protocols and may even achieve enlightenment ;-)
Will your android app be free, and/or any good? Would love to give it a try - Let us know the details when you publish it!
Nick VA3NNW