Being unfriended on Facebook is never pleasant. To smooth things over, Facebook doesn't alert you when it happens (that must be the only thing it doesn't alert you about), however I'm sure most of you would rather know when it does happens.
Defriended does just that.
At every launch it records your list of Facebook friends and compares it to the last one, if someone took off, you're sure to know about it.
It's price? $1.
The awkward encounters that follow its use? Priceless.