Review for Extra Folder Columns by Realraven (Axel Grude)
Rated 5 out of 5 stars
This one is valuable and indispensable. Some people think that this work is done by my extension quickfolders, so I think it would be a good idea if you could upload a preview screenshot (maybe before-after) so people know at a glance what it does.
This review is for a previous version of the add-on (1.1.2).To create your own collections, you must have a Mozilla Add-ons account.