Wails

I don't think there is a free version, but that is exactly what you described. it gives you a 9 week program, it can be Beginner, Intermediate or Advanced and that dictates how long, how far and how much sprinting and walking you do. I did the advanced so it started at 3 mi and 45 minutes long and got longer, but I assume…

Yes, that is actually exactly what it is.

Try an interval running program. It changes it up, gives you new challenges, can be done in the same amount of time, and is even better for weight loss. I love the app that I have used, "Running for Weight Loss", it tells you when you should be running, sprinting, walking and so on as well as tracks your time and distance…