Final Fantasy XIII? There’s an app for that, but it’s not a port or even a game. Square Enix made Final Fantasy XIII – Larger-than-Life Gallery – which is exactly what it sounds like, an image gallery.
This package of wallpapers and concept art costs $8.99 on the iPhone app store. The collection in the Larger-than-Life-Gallery is not in the game or website, but probably in one of the Final Fantasy XIII artbooks. Images from the digital photo album can also be used for your calendar background.