It's not actually a new app, but there is a new internet browser feature that notifies you when someone has unfriended you on Facebook!  The U.K.'s Daily Mail reports that the  free script, called Unfriend Finder, will also tell you when someone has rejected or ignored your friend request.  Gone are the days when you could sneakily and anonymously remove annoying high school classmates and ex-boyfriends from your friends list.  Now, as soon as you do, they’ll be alerted by a red ‘-1’ signal in their web browser window.  Some things are better left unknown.