Generate and store an unique identifier. AppStore-safe.

Use SSKeychain to store the generated string into it. (https://github.com/soffes/sskeychain - Thanks to Sam Soffes).

• Add all clasess to your project
• Import "GMInstallation.h" into your AppDelegate
• Call in application:didFinishLaunchingWithOptions: the next method:

// Generate unique identifier (installation)

[GMInstallation generateOrLoadUUIDForPreKey:@"PREF_KEY_NAME_TO_STORE_THE_UNIQUE_IDENTIFIER"];