1. Please document the issue - jot down a note about how you got there or what you were doing when the issue occurred, if needed, take a screen shot, then please email the issue to us, along with what you've done to try and fix the issue.
2. If you are able to still use your device, and only the app is frozen, force the app to close.
3. Re-enter the app and try to use the app as normal.