GeoGebra 5 on IPad Pro

Hi! Using GeoGebra 5 installed on iPad Pro has reached in a blocked state with a "white/empty" (Retina) screen with no possibility to restart!  A try to get a new installation from Apple Store  only resulted in an "Open" button and new blocked state with a "white/empty" (Retina) screen with no possibility to restart! A problem with Apple rules is that you need a "jailbreak" to uninstall an app. How to solve this failure! Regards Ingmar Olsson