Smartest Bookmarks Bar is a Firefox addon, extends the functionality and usability of the Firefox bookmarks toolbar. It is smart about making it possible to hide the names of Bookmarks and/or Folders on your Bookmarks Toolbar. You can also auto-hide the Bookmarks Toolbar to make the browsing window roomy.
If you would like to align the buttons on the Bookmarks Toolbar to the left, right or center, you can do that too,

Requirements:
* Firefox

The license of this software is Freeware, you can free download and free use this browser plug-ins software.