There has been a lot of websites that help you know your unfollowers on Tumblr. I know I’ve mentioned here about the TumblrStalk, but why open another browser/tab when you can find out who your followers are right there on your dashboard, right?
I now introduce to you the extension that brings you your unfollowers right on to your dashboards: the Missing E.

Missing E
Missing E is a set of tools, features and interface changes for Tumblr. What started out as a bunch of userscripts has been incorporated into a full-pledged browser extension for Chrome, Firefox and Safari.
With this extension, your Tumblr dashboard will be equipped with different tools including the Unfollower finder. You do not need to open a new tab for this nor go to another website because it is already installed on your browser.

"Unfollower" finder on Missing E
By simply clicking the “Δ” beside the number of your followers, you will find out who unfollows you right on your dashboard when you have this Missing E extension installed. But of course, there are limitations.
Click here to install Missing E on your browser now!