Two changes to be aware of…
First - I will no longer update this Tumblr. Since updates are few and far between its easier to keep it under my regular tumblr: donohoe.tumblr.com
Second - I just released the full source of the extension on GitHub. I’m hoping it will be useful. I wrote the code in a hurry so there is plenty to be done in terms of refactoring and cleaning up. It may even push someone to add a Safari or Firefox version if the CSS and other JS based rules can be split into a common area.
Anyway, thought you should know.