From Aviation Data Systems:
Users can enter an aircraft tail number or an FAA flight ID, and a tracking map of the aircraft and its current position appears. To find flights out of a specific airport, users can enter a valid three or four letter FAA airport identifier, and a listing of arrivals and departures in and out of that particular airport will appear. Users can select individual flights to track from the listing. Version 1.3 added more convenient option for tracking commercial flights, option to flip between map and flight details page, improved UI, and includes internal bug fixes and corrections.