I would rate this 5 stars if I didn't have to watch a zip line commercial every time I open the app. It gets very annoying if you have to close the app repeatedly in order to answer your phone and such. Get rid of the ads and I'll rate 5 stars.
It's buggy though. Likes to start playing when it feels like it. You have to kill it to make sure it doesn't start playing randomly. Otherwise good app. 5 stars once the bugs are worked out.