Iphone app does not work

I have been trying for months to use COW on my Iphone and it does not work. I would open the app and attempt to log on using Facebook. Once I get verification from Facebook, COW would attempt to open but stops on a white screen. I've attempted uninstalling COW, restarting my phone, updating my phone, and every other trick I know. It is very frustrating especially when I'm at work and cannot check during attacks and wars. Can anybody help?? PLEASE!!!