Frequently Asked Questions
What do I do if the app cannot be updated on the iPhone or iPad?
In fact, the App Store on iPhone, iPad, or Mac can sometimes get ‘stuck’ and fail to update apps. In this case, deleting the app, restarting the device, and then reinstalling the app usually helps. You may also need to select ‘Restore Purchases’ in the app afterward.
Apple provides further information here: https://support.apple.com/de-de/HT201398