Rated 5 out of 5 stars

** update **
In my first review I mentioned not being able to check out all the functions because of a hotkey conflict. Well, DOH! Apologies for not reading thoroughly enough!
***** And so an update to 5 stars here! ***** You can access the NumExt additional features via the "Tools" menu. Super! :)

A question I have now is: should NumExt save the colors assigned when Firefox is restarted? (if not, if possible, this would be a nice tweak)

Also, a nice feature would be the ability to hotkey to the last/end tab (for when more than 17 tabs are open). Even if the hotkey Alt+9 was designated for that tab (rather than 17). As I recall (?), Firefox designates Ctrl+9 to go to the last tab if more than 9 are open.

Thanks again for a very enjoyable addon! Apologies for any negative effect from my first post.

This review is for a previous version of the add-on (0.6.3).