my app wont open on my ipod touch 4G

i have been playing the game clash of clans on my ipod touch 4G for about a year without any issues until recently. the app wont open and i have tried reinstalling it, rebooting my ipod and deleting some of the other apps to make room in my storage. What happens is i will tap on the app and it will bring me to the loading screen but then freeze for about a half a second and then abruptly send me back to the home screen. i am only having problems with this one app, the rest are working perfectly fine. i spent money on the app and i really want to get it fixed. any suggestions?