Nice add-on - be careful removing Rated 4 out of 5 stars
This add-on adds a single new feature, the ability to make a tab "permanent". You can't delete it (no "X" on it or "close tab" menu option) and even a restart won't make it go away. Love it for my GMail inbox and home page.
The only problem is that if you remove it (I had to temporarily remove it for administrative problems), be sure you have no permanent tabs left. Because, the tabs stay permanent but you have no way to disable it. Probably a bug but only a minor one as you can reinstall, uncheck the "permanent tab" menu item, and then re-remove it.