Only released in EOL distros:
Package Summary
 Documented 
The gd_msgs package
- Maintainer status: maintained
 - Maintainer: RoboSavvy <info AT robosavvy DOT com>
 - Author:
 - License: Creative Commons Attribution 3.0
 - Source: git https://github.com/robosavvy/gd_msgs.git (branch: master)
 
Contents
RoboSavvy's self-balance platform common package.
Tutorials here.