Driver Assist helps you to control different features which are useful by driving a car. It will control GPS, Mobile Data, Airplane Mode, Bluetooth, Blitzer.de automatically if you are need it during driving some vehicle. Of course, you can choose which feature should be controlled and which not by selecting the appropriate one in the settings menu.
Remark: GPS, Airplane mode and Mobile Data are just controlled automatically, if your phone is rooted! If not, GPS has to be enabled manually in order to have the chance to use Blitzer.de.
Condition: Just plugin your charging cable and the app will recognize whether you are actually driving or just loading your battery. Unplug your cable and the app will deactivate themself till next time loading the battery.