Operating state information is received at an on-board telematics control unit (TCU) from an on-board diagnostic (OBD) system of a vehicle. The TCU transmits an indication of vehicle state over at least a wireless data link component of a communications network for delivery to a mobile computing device. The mobile computing device receives the indication of vehicle state and utilizes the indication of vehicle state at a mobile application program. In one example, the mobile application program presents vehicle state information via a graphical display of the mobile computing device. In another example, the mobile application program augments a functionality of the mobile computing device responsive to the indication of vehicle state.