This article discusses software internally used by Apple.
Acquiring a copy without Apple's consent is illegal and may result in being scammed.
Mesa Demo is an application that is somewhat of an evolution from the Mesa Utility application. It offers a more refined UI, and once again while present on SwitchBoard builds it is not shown due to the fact it is designed for UI builds. This app was most likely the last stepping stone before Touch-ID was integrated with the lock screen.