Blick Radar

Once you turn it ON it stays armed — if you close the app or restart your phone, it automatically resumes tracking the moment you open it again, no tapping needed. It stays on until you hit Stop. (Heads-up: while the app is fully closed it can't watch your GPS — browsers don't allow that — but it re-arms itself instantly on reopen.) Keep the app open/running while driving; the screen can sleep, we hold a wake-lock.