How do these apps work, in practice? The article states:

> If you’re at the wheel focused on the road, but someone in the passenger seat is changing the music on your phone, the app may think it’s observing distracted driving and count it against you.

Is the app running on the car, or on the user's phone, which somehow detects that the user is driving a car? Is there some way that a paired phone (Bluetooth - or maybe this is a feature of CarPlay / Android Auto) can tell a car that it's being used?