I have the Active.com couch to 5k app for my Iphone 5C. It also lets you listen to your own music as well. You can use it with a treadmill by just having it give you commands by time and you then log the miles you ran at the end. Or you can use it with your GPS turned on to log time and actual distance if running outside. I really like it. Starts with a 1 min run, 90 sec walk interval and works up to constant running at the end. All workouts are about half hour and have a walk to begin and cool down.