Problem with the app

Well,I have an iPod touch 5 gen. and I bought this app. I cant purchase any other guns because I have a problem when touching the OK button. I used it in my iPad and it did work, so I am asking if you could make an update so it is compatible with iPod touch 5 gen iOS 6 and later.

GlitchingLord about i-Gun Ultimate - Original Gun App Sensation, v1.43