What happens when a phone call comes in?

Apple® shuts down all third party apps when a call comes in. MotionX-GPS saves your current state, and once the call is finished, you are returned to where you were. Your stopwatch will still be running, and we will include the distance between the last point before the call came in and your current location. However, it will be calculated based on a straight line since the GPS signal is not available during a call.