The app kicks in at speeds over 10 mph, as determined by GPS coordinates and cell tower triangulation. Once in lockdown mode, Drive First disables phone functions and email and text alerts. All incoming calls are sent to voicemail, and if you get a text message while on the road, the app automatically replies to notify the sender that you’re currently driving. (The auto-reply can be customized.) You won’t regain access to your phone until the car has completely stopped moving for a few minutes, to account for stop-and-go traffic.
If you really want access to your phone while driving, there is an exit button as well as a 911 button that overrides the app.
If you are a concerned parent, the app can notify you about any override of the app.
The service isn’t free, though. It costs Sprint subscribers $2 extra per month per phone. For now, Drive First works only with Sprint smartphones running the Android operation system, though BlackBerry devices will get the service in the future.