I used it paired with Nikeplus and Endomondo, because I couldnt set my own intervals there. This app helped me with it.
Its very simple to set everything and use it, and there are many possibilities. You can set intervals for any wanted time, choose from many different sound signals, and theres a music player integrated with iPhones player.
The app generally work fine even in the background, but one or two times it freezed, making me run longer than I was supposed to. If you keep other apps closed though (for example only Nikeplus and Interval Timer open), there shouldnt be any problems.
Thank you for this app! It was really a huge help for me when I was starting running.
Szwajewski about Interval Timer - Tabata Timer, v3.0.2