Review for Compact Menu 2 by WildcatRay
Rated 4 out of 5 stars
Very nice.
I do have a tip for anyone who also uses the Personal Menu extension (https://addons.mozilla.org/en-US/firefox/addon/3895). To hide the Menu Bar, you will need to go into Personal Menu's options/preferences, go to the Advanced tab and check the Hide Menus Toolbar.
Evidently, Personal Menu overrides the hide prefs in Compact Menu and Firefox.
To create your own collections, you must have a Mozilla Add-ons account.