Not exactly the same feature. It would only notify both users if they mutually assigned each other as crushs.
They removed this and other features completely in the new redesign from last year.
What's the difference?
The OP's app sends a message telling the user that someone has a crush on him/her. Orkut would only send a message if both users marked themselves as crushs.
Both hotornot (with its Meet Me service) and okcupid have features with some similarities, too (although in both cases, you are rating profiles on their site for people who you most likely don't know IRL instead of entering e-mail addresses of people you know.)
Oh ok I didn't know, I gonna take a look. Thank you for the tips :)