Similar to Facebook app? Those don't even really make sense since Facebook is a social network site where D&D is a game property.
Sigh... It's called D&D Tiny Adventures. Google it.
OOOOOOH! You're talking about the D&D app for FACEBOOK not the Facebook app for the iPhone.
<3 Tiny Adventures. I died a lot though.
I've heard of that, but never thought it was worth making a Facebook to play. Am I wrong?
D&D Home Page - What Class Are You? - Build A Character - D&D Compendium
Take a look at this for a really well made D&D "app" for the iPhone.
There's a typo in your URL. It's supposed to be iplay4e.appspot.com
Well, it's actually a website that you go visit, but since the iPhone requires an internet plan, it's no big deal.