Roomy Bookmarks Toolbar
What does this tool do: Allows quick access to bookmarks while hiding them from view…and much more.
Looksee Page: https://addons.mozilla.org/en-US/firefox/addon/roomy-bookmarks-toolbar/?src=userprofile
Comments: This addon is much more valuable than may be obvious at first. It allows you to do many things you had never even considered before, but ends up saving you “real estate” and time in accessing your saved bookmarks. Among many options, you can hide (or not) multi-rows and names of bookmarks and save space by sizing and squeezing bookmark folders. Check this out.