GBX.lua.CoreGui (Service)
From Goodblox Wiki
Preliminary: This item was still under development in this version of Roblox. Use only for experimental work.
Note: This is a Game Service, and therefore isn't like other Objects in the Class Explorer. You have to call it with :
game:GetService("<Service name>")
The CoreGui is... something.
Functions
The CoreGui object only incorporates the global functions.
Properties
The CoreGui only incorporates global properties.
Events
The CoreGui object only incorporates the global events.