Sometimes, you’ll run into a great feature in one of the stock Apple apps and be stumped as to how they’ve implemented it. The page curl animation effect in iBooks is one of them, and while Apple’s own implementation appears to be using private APIs, the community has already gone ahead and produced an App Store safe version that does not rely on private APIs.
Tom Brow initially created a project for an iBooks-like page turning interface called Leaves, which was later branched by Ole Begemann to support 2 side by side pages in landscape mode.
John from ManiacDev has a screencast showing the two page variant in action.
