伴隨着iOS的每次升級，都有不少API更新，程序可能也需要相應的修改。
面對麻煩，只有快速地解決麻煩：
iOS 5 Beta 2 API Diffs （非官方）
iOS 4.2 to iOS 4.3 API Differences
iOS 4.1 to iOS 4.2 API Differences
iOS 4.0 to iOS 4.1 API Differences
iOS 3.2 to iOS 4.0 API Differences
iOS 3.1 to iOS 3.2 API Differences
iOS 3.0 to iOS 3.1 API Differences
iOS 2.2 to iOS 3.0 API Differences
iOS 2.1 to iOS 2.2 API Differences