For Android device,  include only one application in your kiosk/lockdown-mode. Then either disable in device's "Settings" or blacklist (e.g. with application-run-control profile payload)  all unwanted apps, including bundled/installed apps and possibly modules related to system services.  However, you have to do thorough testing on stability because disallowing some kernel/system modules from running may crash your system unexpectedly at seemingly random scenario or when the device end-user has performed some specific sequence of actions.