Hi ​@Barnesy, try turning your device off and on when reinstalling the app (uninstall > turn off > turn on > install). There could be some stuck/looped process that's causing the crashes, and this way you’d get rid of it. 

If it doesn't help, yet double check for free space on the device, or any recently installed new apps that might potentially be conflicting.

No changes on my device since I last opened the app that I can remember but alas the classic "turn it off and on again" trick worked. Should've thought of that

Cheers for the reply ​@Jana_S