The Booster Flashlight is a module of the Boosting locomotion; it provides a particular functionality for its parent Booster. If it is disabled or removed, then the relevant boosting functionality will behave as by default. Most modules can optionally affect change globally (for both hands' Boosters). Booster modules can also depend upon conditions specified by their dependencies settings.
The Flashlight module uses the BoosterLight class to control a light which can serve as a flashlight, to aid with visibility in dark scenes or what have you.