Every now and then, we see guidance used in products that is great for someone’s first time, but continues to help people complete actions on subsequent users. This is an example of such continued guidance in the iOS App Store from App.
To introduce users to the concept of confirming installs via Face ID, the app shows an overlay with guidance to “Confirm with Side Button,” at the same time that a coachmark appears on screen to the left of the power button, indicating that the button should be double-clicked twice. This will initiate the Face ID scan, with realtime feedback in the place of the “Confirm with Side Button” area on the overlay to confirm or suggest trying again.