Update 9.9.7 fixes a problem if you quit and try to restart. The app will hang at the next game point where you can stop the Charleston. It was trying to stop the game instead of just the Charleston. This update is currently being reviewed by Apple.

This only affects iOS devices because iOS does not let an app quit (there is no quit function) iOS apps can only be stopped by the user. (Swipe up from the bottom edge, then over to the right, and swipe the app off the display). Apple intends for apps to remain running after they are started. When apps are minimized, they do not use many resouces.