The Hoverboards addon for Garry's Mod. This addon was not initially created by me, it was only fixed up and ported to GMod 13 by me.
The original authors as I could find are:
- Foszor
- Jinto.
You do not need to download and install this addon manually, it is available on the Steam Workshop: https://steamcommunity.com/sharedfiles/filedetails/?id=150455514
Simply press the green + Subscribe button on the addon page and it will be automatically downloaded when you next start Garry's Mod.