SuperSorter - Clean up your bookmark mess!
Linkman - Linkman Pro allows for managing large amount of URLs in its own database.
Fast Bookmark Scanner II - Scan your bookmarks in order to delete duplicated links empty folders or merge duplicated folders.
Firefox Sync - Bring your Firefox bookmarks, tabs, or passwords wherever you go with Firefox Sync. Share between computers and mobile devices. Get Firefox now!
Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.