Before I could give her the freshly grandparent-proofed device, said video calling app upgraded on my parents' PC first and changed literally every single element of the UI beyond recognition. To someone the age of my grandma, that would be literally like bricking the device remotely, because none of the buttons would look the same, and she would not be able to work out how to use the new interface.
STOP CHANGING THINGS! Even if the new UI is better (debatable), some people just like or rely on a particular layout to operate the device or app. Don't rearrange without giving a ~permanent setting to use the old layout.