Tap the screen to calculate the tempo -- then play it back with the built-in metronome!
Tap Tempo+ is the most accurate tempo calculator on the market. Simply tap a button and it will derive the tempo using the most accurate algorithm there is.
The app is a full-fledged metronome. You can set the time signature and choose from a variety of high quality sound sample sets. The screen flashes in time with the beat so you can use it with the volume off.