Flightradar24 is a nifty app for watching commercial flights take place in real time using just your mobile device. In the main interface of the app, you'll see a map of the world, complete with plane blips signifying flights that are currently in transit.

The free version of the app does not include certain details pertaining to the flights you see, including arrival and departure times, destination information, or point of origin. However, you can search the map for particular flights. With Flightradar24, you're free to zoom anywhere on the map and see what's happening in the air at that exact time.

For enthusiasts who love all things flying, Flightradar24 is a terrific app that's both addicting and can kill lots of time.