Rated 5 out of 5 stars

Great add-on. Good to see it's still being developed.
To reviewer "fusumooyu", below, the $ 0.99 is NOT mandatory. The download error you may see has nothing to do with not having donated. Try downloading from the "View Older Versions" page (https://addons.mozilla.org/en-US/firefox/addons/versions/6349)

This review is for a previous version of the add-on (2.2.1-signed.1-signed).