Training good my first marathon and my running coach recommended a 160 tempo to prevent injury. This is perfect for me, it plays in the background if you want to use your own playlist, but I find the rhythm easier to follow without music. It doesnt interfere with my mapping apps which is a huge plus. To save battery I blacken the screen when in use and set the timer. Highly recommend!
SylviaAP73 about Run Tempo - Runners Metronome