Users will be able to lock an app when they hand over their phone to do things like show someone a picture or let them play a game. When an app is locked, if someone tries to tap the phone, they will be required to authenticate using Face ID, Touch ID or a passcode.
While the app lock feature is enabled, information from inside the app won’t appear in other places, like search and notifications. Users can also hide an app that they don’t want others to know is installed. The hidden apps appear in a hidden, locked folder.
Wow yet another feature android had like 4 years ago!