THIS is what Windows Phone needs!
No, not the app. But just look at it! It looks positively delicious. Look at the animations, and how the elements on the app respond to touch inputs. It looks breathtaking.
I'm going to go out on a limb here and say that this is technically not possible on Windows Phone. There is no, not a single app on the Store, not even those developed by Microsoft or hardcore third party developers, that can do this. We talk about how the UI on Windows Phone in beautiful, and apps do look beautiful visually. But I really think Microsoft needs to do something to allow developers to make such interactive apps.