Review for Nostalgy by Matt Postiff
Rated 5 out of 5 stars
Nostalgy is a great add-on. I use it all the time.
The default color scheme doesn't work too well with TB5. When I press 's' to save a message, then arrow up in the provided list of folders, the folder name that is selected becomes unreadable. It is white text on a transparent/very light blue background (I think, I cannot tell very well). The way it was in TB3 was much better.
To create your own collections, you must have a Mozilla Add-ons account.