Mix Master: PaceDJ
If your musical taste is all over the place, building a playlist that keeps you moving at a steady pace can be a challenge. PaceDJ scans your music archive, breaks down all the songs by beats per minute, and then creates a playlist to match the preferred tempo of your run. If you're not sure about your tempo, the app can measure your running or walking speed to determine your target bpm range. An interval training mode lets you switch things up to customize your own workout.$2.99; iOS, Android