Rated 4 out of 5 stars

Very good tool, especially for studying Firefox's own chrome. Extension description should highlight this feature as it isn't at all obvious. So far the best tool I've found that lets you study firefox UI styling from within Firefox itself. Working for me with FF30+.

One issue (minor): after shift-right-click on some Firefox chrome, the Inspector's topmost bar (the > horizontal > bar > showing > the > style > hierarchy) can't be focused, it goes black or blanks out before you can mouse to it or use it. Apart from that, brilliant for studying and fixing chrome and UI issues!

This review is for a previous version of the add-on (0.0.6.1-signed).