Ver 2 is for maintenance only now.
New version, GPS-Trk ver 3 was released as a different app.
https://itunes.apple.com/us/app/gps-trk-3/id1064777208?ls=1&mt=8
(No free update from ver 2. Ver 2 will be continuously usable.)
[Continued use of GPS running in the background can dramatically decrease battery life.]