I got this app because people reviewed it as being great and almost flawless. After trying it for myself, I realized that it still needs a lot of work. If youre like me and dont download music, and instead you use Spotify, youre out of luck because it only works with music thats on your phone. But if youre like me, and you still need music to run regardless or else it gets boring real quick, you can use spotify still BUT it makes playing this game more difficult. I attempted to use both but sometimes the storyline would delay (so you have to pause/unpause every once in a while) and it would only sometimes interrupt my music (which is what you want). I also tried to stop my first mission, and it told me that I could return to where I left off. However, it restarted the mission even when I clicked to continue it. Also, Im using iOS 7, and Ive had a few issues with opening the app. The screen stays black for the longest time, and sometimes crashes, but once its open and loaded its usually good to go. So overall, the app still needs a lot of tweaking and fixing bugs but its a great concept.