After app launched for a long time, there are some logs in console while touching the screen:
BKSendHIDEvent: IOHIDEventSystemConnectionDispatchEvent error:0xE
I have the same problem.
In My case it happends after switch off wifi in iPad (OS 9.1). Application is unresponsive. In console I can see the same errors.
After switch wifi on, application is again responsive and I can continue.