iOS Guided Access

http://www.groovypost.com/howto/lock-down-ipad-iphone-one-app-only/
http://learninginhand.com/blog/limit-an-ios-device-to-running-a-single-app.html
https://support.apple.com/en-sg/HT202612
http://www.imore.com/how-restrict-access-specific-app-guided-access-iphone-and-ipad
http://9to5mac.com/2013/09/08/how-to-use-ioss-guided-access-feature/