Update 2/23/11:
According to TechCrunch, Breakup Notifier was shutdown by Facebook today. The app had collected 3.6 million users in the 2ish days it was active.
Original Post 2/21/11:
Love-seekers and gossipers: Do I have an app for you!
I just read about Breakup Notifier, which has the most self-explanatory name in app history, in the Huffington Post. Its an interesting use of Facebook's API.
The app is simple- Sign in to the app using your Facebook log in; Choose which friends you would like to monitor and receive an email whenever their relationship status changes.
There you have it. Good Luck?