I’m not one of the sort of folks that gets irritated when people unfollow me on Twitter, but I do like to keep track of it. Qwitter used to provide that service, but it’s been absent without leave for a good long while.
So I hacked together a little Ruby script that when run shows me the folks that have unfollowed me since the last run and a little info on them. Just add your username / password right up there at the top and let the disgruntledness begin! Enjoy.