I’m going to show you in this post how to write a workaround for this problem. Many of the existing Apps in the App Store are dependent on this property (uniqueIdentifier) for uniquely identifying a particular device… Apple stopped supporting a unique identifier for iOS (>=5.0).
But wait… where does this property it come from? The following source code solves the problem. It generates a unique identifier based on the mac address of the device in combination with the bundle identifier.