Review for Extra Folder Columns by magnosis
Rated 2 out of 5 stars
Very useful, but annoying as it breaks the Smart Folder view (if I enable EFC then TB stops displaying the name of the account for each folders in Smart Folder).
I use multiple (6) accounts in TB and thus I now only get 6 folders called "inbox". Please fix this.
To create your own collections, you must have a Mozilla Add-ons account.