I have an app that sometimes hangs when my signal is bad, it gets stuck on a black screen and i can't access it's menu or anything and the phones 'back/escape key' does not work... The black screen will just stay like that forever until it picks up a signal (the app is actually online - i access it via the phone). I *can use 'ALT + Back Key' for the phone's home screen etc..... Is there any way to turn off the app without restarting the phone?