I need a refund!

I played Lets Golf on my old iPod touch and found it very fun. I downloaded it here, and played one game and the app crashed. I redownloaded it from the store and opened it again a few times. Everytime I do this, a message comes up saying "Lets Golf 2 is damaged and cant be opened. Delete Lets Golf 2 and download it again from the App Store." Whats up with that?

Tommy Schubert about Let's Golf! 2, v1.0.0