It's probably not the only tool out there which allows us to see our dead followers, but I've just came across it and used it. Steem.Agency is a website created by @SirCork, to showcase the contributions

How to know your dead followers Put the url below then put your steem username How to know the exact time of high activity of your followers 1 Use this link 2 put your username instead of (steemit-earn)