This article discusses software internally used by Apple.
Acquiring a copy without Apple's consent is illegal and may result in being scammed.
Mesa Utility is an application that is shipped with SwitchBoard, but is not present on the SwitchBoard screen as it is designed for UI builds. This app was presumably used to test Touch ID back in the earlier days before it was integrated into the lock screen. It has a very basic UI, lacking in the refinement.