You heard about it, most likely, when it was being toyed with a while back. Now it’s available for download (free) in Apple’s App Store. The “it” is “at,” as in WhereTheLadies.at from Jeff Hodson and Danny Trinh.
I think I can boil down the app thusly: A big red pointer guides you to clusters of females who have recently checked in to Foursquare. Done.
Use that information for what you will. Call it genius or call it heinous. Just don’t call it difficult to use.
Now if I could only have an app to point me in the direction of the nearest place to safely take a nap…