With iPads you may have an issue because your app is older (update the app).
Most often, you develop app issues because you've taxed your iPads capabilities. When that happens you need to do a restart.
1. Close all apps (swipe up to close).
2. Power down.
3. Wait 30 seconds.
4. Power up.
This will take care of many, many iPad issues.
Sometimes you will get a "white screen". When this happens there was a hiccup in updating your app. You may need to uninstall and reinstall the Boom Cards app to fix the problem.