[iOS] iCloud

1. Enable iCloud Storage on Provision file.
2. Turning on iCloud entitlement
3. Remove the Apps with previous version on devices.
4. An example to store/fetch key-value iCloud.
How to check if iCloud is configured programmatically.
5. iCloud: Backup and restore overview.
6. Getting Start with iCloud Storage.
7. About File Metadata Queries.
8. Your Third iOS App.
9. Filesystem Programming Guide.
10. About Document-Based Applications in iOS.

iOS App Programming Guide: iCloud
iCloud - Apple Developer
Tools Workflow Guide for Mac
iCloud Design Guide
Turning On Applications Entitlements

If everything not goes well, try delete ~/Library/Containers/.