Shows an 'Unread' button to filter emails by 'Unread' status.
Image from store
Latest issues
(2020-05-23, v:1.0) Karl Hansen (a2brute): Is this extension still working? I really like this idea, and have been looking for something similar now and then for years. So I load it up, but no button appears. I suspect the extension has not been updated as GMail changes over time.