Sync settings through iCloud key-value storage.

Similar to @AppStorage and @SceneStorage in iOS14, this @CloudStorage property wrapper persists values across app restarts. But this also synchronizes these values across devices using iCloud Key-Value Storage.

Make sure you enable the "key-value storage" service in the iCloud capability. See Apple's documentation

@CloudStorage("readyForAction") var readyForAction: Bool = false
@CloudStorage("numberOfItems") var numberOfItems: Int = 0
@CloudStorage("orientation") var orientation: String?

See also the example app in this repository.

The same caveats apply as with key-value storage itself:

Key-value storage is for discrete values such as preferences, settings, and simple app state.

Use iCloud key-value storage for small amounts of data: stocks or weather information, locations, bookmarks, a recent documents list, settings and preferences, and simple game state. Every app submitted to the App Store or Mac App Store should take advantage of key-value storage.

From Apple's documenation on choosing the proper iCloud Storage API

In general, key-value storage is not meant as a general purpose syncing service. If you need any advanced capabilities to prevent data loss, consider using CloudKit instead.