An app designed to prevent using distracting phone functionality, including texting, on a mobile phone while driving a vehicle is disclosed. The app detects and measure attributes including the phone's orientation and change of orientation and expresses them in a coordinate system relative to the direction of motion of the vehicle. If the phone orientation is found to be consistent with a change in direction of the vehicle, or the axis of rotation of the phone is found to be consistent with itself over time, the distracting phone functionality is disabled.