FlightAware Flight Tracker: Tracking all airline flights, flight status, Gate/Terminal information, delays, cancellations, etc. It’s freeware.
FlightView Free: Free Flight tracking app from the leaders in real-time flight information (Real-Time Flight Tracker and Airport Delay Status).It’s freeware.
Liligo flight and hotel search: An app searching for cheap flight, hotel or car hire.
SeatGuru by TripAdvisor: An app for seat map advice, flight status and buying tickets at the lowest prices.
Wizzair Search and Price Alert: Searches for low cost Wizzair flights or creates Price Alerts to know when the price decreases below the price you want.