Good Tool. Would have rated it higher but,
1. Exported themes won't install, they have to be signed by mozilla (a long winded process) and
2. The page layout for the popup menu box example, hides the saved themes option, making it impossible to select/change themes without zooming the page right down.

That said, exported and signed theme did install and work well. not really for novices.

If devs can fix these issues, its a excellent tool.