@unfollowr command center
See who unfollows you on twitter for free.
What is it? @unfollowr is the twitter service that helps you to track people that stopped following you.
No more guessing "who unfollowed me today?" — you'll know that for sure with @unfollowr.
You will receive emails with list of unfollowers (including ex-friends).
All your need to start is to follow @unfollowr and authorize it to find your unfollowers.