In short, Facebook has managed to fully port the signature confusion of its website to a tablet app, a not insignificant achievement.
Siegler, who found the app after reading about it on Twitter, calls the app "spectacular." The discovery was made by a an engineering student named Marvin Bernal, who also gives instructions on how to get it running on your own iPad.
If you are smart enough to know what that means, and yet you still use Facebook, then go ahead and hack away.
More here: Facebook iPad app hidden inside iPhone app - CNN.com