iOS 5.0: iCloud (Programming iOS)

This tutorial will teach you how to set up your app to use iCloud to store app data. It describes how to obtain a provisioning profile and iCloud entitlements. It explains Grand Central Dispatch, NSMetadataQuery objects, and notifications. It describes the requirements for subclassing the UIDocument class and explains how to create, write to, read from, copy, move, and delete iCloud files and how to monitor iCloud directories. It demonstrates how to save and access key-value pairs in iCloud, explains how to avoid conflicts between versions of the same iCloud file, and discusses iCloud app debugging and design.