Download here: https://play.google.com/store/apps/details?id=org.droidplanner.andr...
Follow here: http://discuss.ardupilot.org/t/tower-v4-0-0-beta-1-released/11228
Beta 1 for Tower v4.0.0 is now available on the Play Store5!
Here are some of the highlights for this release:
Remove dependency on 3DR Services
Compass calibration support for Solo and ArduCopter v3.4 or higher
Restore vehicle history screen
Ability to export the vehicle flight path as a mission
Deprecate '.dpwp' mission file for '.txt' mission file to improve compatibility with other GCS
Autosave last survey preferences
Fix invalid altitude frame for Follow-Me and Guided mode
Fix Takeoff mission waypoint for plane vehicles
The full changelog can be found on github6.