I'm making a free version of a game app, and in part to stimulate purchase of the full version, and in part because I don't want to have two separate leaderboards for what is essentially the same game, I decided to leave Game Center out of the free version.
My specific question is: In the full version, I've got a 'leaderboard' button that links to the Game Center high scores. In the lite version, will Apple reject me if I leave that button there, but have it display a pop-up saying that particular feature is only available in the full version? Or would I be better off just to delete that button entirely from the lite version?
Off the top of my head, I'd say no. Apple has no right to deny you from leaving out paid features. If you don't trust me, or need a second, more authoritative opinion, scan the Apple HIG. (Although really, how hard is it to set the alpha of a button to 0.0f?).
EDIT; Having looked over the HIG, I can say that you could go either way. The solution involving keeping the button would alert the user to the fact that they are using the lite version of the app, and possibly allow them the option to purchase the feature you've kept from them. It's good design either way, one just makes you a little more money :P