This add-on does a good job at listing your add-ons and displaying for each the permissions granted by Firefox and you can list by add-on or by permission and that's very nice.

But it's a confusing experience altogether because the listed permissions for an add-on sometimes aren't the same as the ones Firefox reports as being used by the add-on (for example "Search Bookmarks Button" add-on is reported by this add-on as being able to "can access data from any active tab and can inject code and style to active tab" while the add-on and Firefox do not report this permission as being used, so who's right? Confusing. Also, the wording used is different. This add-on uses different wording than Firefox does, so this adds to the confusion when trying to understand the permissions used by an add-on.
One last thing, it would be nice to have all the inactive add-ons listed at the bottom like Firefox does. Thx!