Guided Access is a built-in Apple feature that pins an iPad or iPhone to a single app and blocks the home gesture, so a person using the device cannot leave that app. Agents pair it with an open house sign-in app to keep an unattended iPad on the form.
Combined with an app that has its own PIN-locked kiosk mode, Guided Access makes the entry-table tablet about as foolproof as a paper clipboard: visitors sign in and cannot wander into your photos, messages, or other apps.