- Android: On devices with Android 5.0 or newer , there is the possibility of locking down an App/browser until you enter a pin or a pattern.
Settings - Security - Advanced/Other security settings - Pin window
Tap 'Overview' button tap the pin on the bottom right corner on the app's card. Press 'Back' and 'Overview' button at the same time to unpin.
- Fully Kiosk Browser: this App allows to limit the use of the device to one and only window/app/web page preventing from accesing other apps/settings/buttons. Also scaling, locking and so many other features.