The Rig GUI developed by Sakura is a collection of UI Scripts used almost exclusively on Sakura's rigs, although it is possible to add configs to other rigs by mimicking SACR's Custom Property Structure.
The Rig GUI was first made exclusively for SACR R7.2 as a quality of life upgrade so that the rig settings can be access from any bone.
The GUI is available officially through Blender Extensions or you can download direct from here
Download Rig GUI Addon