The phone GPS activates OFF when car reaches a certain speed, unless the administrator over rides it...it's password protected. Charging does not matter. Riding a bike, skateboard...OFF.
I think they said in the webcast this happens at 3+ MPH. The OPMG PhoneGuard DriveSafe app does this at 10 MPH, and I think the SPBU app coming out Oct 31 is also 10 MPH.
NUNCHI does sense ambient sound though and can be set up to activate OFF.