Let me see whether I understand. You want to modify the appearance of '''the Bookmarks Toolbar''' to be like your picture, plus additional functionality. * Bookmark names (text) should be hidden until you mouse over the icon * Names should appear (next to / below?) the icon when you hover it with the mouse Is that right? These kinds of changes aren't supported by built-in features or add-ons, but you can make those modifications using the community-supported userChrome.css file. A good place to search and request such rules is this subreddit: https://www.reddit.com/r/FirefoxCSS I have a general site about userChrome.css here: https://www.userchrome.org/