Phone app that tracks planes ‘is aid to terrorists armed with missiles’ says security expert. Plane Finder AR app allows users to point their phone at the sky and see the position, height and speed of nearby aircraft. It also shows the airline, flight number, departure point, destination and even the likely course. The program was developed by a British firm and sold for just 1.79 in the online Apple store. It was last night labelled an ‘aid to terrorists’ amid fears it could be used to target an aircraft with a missile.”]