Bookmarks LinkChecker 0.6.8.4
Unfortunately, due to bug 385712, the Places Tree View does not currently allow custom columns! With that news, this extension cannot be updated for v3.
Updated from v0.6.8, extension 'Bookmark Link Checker' detects updated, redirected, and broken links in your bookmarks list by adding icons within the drop-down bookmarks menu. ...
This add-on is not compatible with your version of Firefox because of the following: