useful info Rated 4 out of 5 stars

This is useful info, and I am looking forward to it being included in natively (which is https://bugzilla.mozilla.org/show_bug.cgi?id=661881).
The current addon does cause a spurious "unable to read chrome.manifest" error in the nightlies (similar to https://bugzilla.mozilla.org/show_bug.cgi?id=586610).

This review is for a previous version of the add-on (0.6).