Welcome back Unfriend Checker, as the add-on is now working again with Firefox, and fully compatible with the new Facebook! It'll now go over your friends list via the mobile version of the site, which takes no more than a few minutes to complete, give or take, and depending on how many friends you have. Though it now tells you that you "lost" a friend when someone merely deactivates, which means you'll have to sift through all the names to see who (if anyone) actually removed you. But other than that it's great this works once more, and highly recommended to use too. :)

This extension no longer working in new Facebook layout.

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