FollowerMonitor is a Twitter bot account that tells you when someone has stopped following you. Great service to monitor who unfollows you. You need to follow FollowerMonitor to start getting tweets about your unfollowers.
An alternative solution for the currently not working service Qwitter.
Pros & Cons
|Doesn’t need your Twitter credentials||Can be annoying in case you follow known Twitter account and it gets many unfollowers. Then you’ll get all FollowerMonitor tweets about this known Twitter account|
|Great idea and simple to use||Sends you a reply containing the unfollower Twitter account, which is also receivable by the unfollower. Direct messaging would be better|
|Sends the reply after a long time from the unfollow action (sometimes hours)|