The iOS 6 was launched with about 200+ new features and one of those is Guided Access. Guided Access restricts users to focus over a specific task or content by disabling access to the other areas of iPhone and iPad screen, which is quite helpful in some specific situations.
Guided Access helps students with disabilities such as autism remain on task and focused on content. It allows a parent, teacher, or administrator to limit an iOS device to one app by disabling the Home button, as well as restrict touch input on certain areas of the screen.
So, here is a guide which helps you to enable guided access on iPhone and iPad over iOS 6+.
Enable Guided Access on iPhone and iPad
Tap on “Settings” app from Springboard
Navigate through “General” > “Accessibility”, tap “Guided Access” and set it to “On” state
Guide Access is enabled on your iPhone and iPad on iOS 6+.
Note: If you have enabled Guided Access on your iDevice then it would be a better approach to set a passcode as well, so that no one can leave the session through guided access either your iDevice goes into sleep mode. You can learn the process to set Passcode on iPhone or iPad by visiting following link.