Does what it says on the tin, and adds icons to folders in the blueprint library and the toolbar. It does this by adding a .spz2meta file to each folder that stores the icon, so in the future I could maybe add different kinds of metadata to folders. The icons can be edited exactly the same as the blueprints; If you leave the icon empty, it renders the vanilla folder icon.

Does not currently have an official release, you'll have to build it yourself. It's planned to be posted on Steam Workshop, I'm just waiting for the competition to properly start and to see if I get accepted.