Rated 4 out of 5 stars

"Known issues: Dark Personas or Themes cause an unreadable text in the add-on bar."

Just for the record, I have the same problem with the standard theme. I just see a large blank space in the add-on bar where the extension display should be. (Current Firefox Aurora on Windows, but I recall having the same problem on the release version. What FF versions is this known to display correctly in?)

It is nice to be able to trigger CC and GC on demand.

For a future rev, it would be nice to replace the display block with an icon, that would show the display block in a tooltip if moused over. Have enough addons, and you begrudge the space taken in the bar

This review is for a previous version of the add-on (0.5.1.1-signed). 

The theme issue should have been fixed a while back. If you install a dark theme you will have to restart Firefox. Then you should see a light color for the text. Doesn't that happen?

Upcoming versions of the SDK will not allow addons to put that much information in the bar. Once that feature has been shipped your enhancement request will automatically be fulfilled.

Thanks for your feedback!