UnfriendApp is a free application that notifies you whenever someone unfriends you on Facebook.
When someone unfriends you, you'll see a notification showing which one of your friends unfriended you.
If one of your friends deletes their Facebook profile, UnfriendApp will notify you about these changes as well.
After installing, just use Facebook as usual. You'll know UnfriendApp is running when you see it listed on the newsfeed under 'More Apps' (like this).
UnfriendApp checks your friends list every 15 minutes to see who has unfriended you, and then automatically alerts you about any changes.
UnfriendApp works on Windows PC's using Internet Explorer 7+ or FireFox 3.6+.
Your friends list is stored locally in your computer and is never transmitted to us or anyone. Your information stays private and secure.