Hey, judging by the video I don't agree that your app is 'very well polished'. Check out Cut the Rope, that's the kind of polish that is expected from an App Store game.

Suggestions:

- Add a tweening for picking up and dropping letters

- centering of the board should happen automatically

- put the restart button somewhere else. It looks weird when you drop a letter on top of it and it appears behind it (e.g. the 'm' in 'seem')

- can't really tell from the video whether you already did this, but implement iPhone-like scrolling w/ momentum and bouncy behavior