PIN ID or Touch ID
In some cases, I have to set up and manage my colleagues' mobile phones.
It would be helpful if the app (Android or ios) - similar to Threema) would be equipped with a separate lock, so that ignorant can not play around with the settings. (or even uninstall or turn off the app).
Not just for safety from ignorant, but it does make it easier for some who have disabilities. I am talking about the dreaded accidental keystrokes! That would be eliminated with pin/Touch ID.