UIDevice uniqueIdentifier deprecated – What to do now?

It has just come to light that the UIDevice uniqueIdentifier property is deprecated in iOS 5 and unavailable in iOS 7 and above. No alternative method or property appears to be available or forthcoming.

Many of our existing apps are tightly dependent on this property for uniquely identifying a particular device. How might we handle this problem going forward?

The suggestion from the documentation in 2011-2012 was:

Special Considerations

Do not use the uniqueIdentifier property. To create a unique identifier specific
to your app, you can call the CFUUIDCreate function to create a UUID, and write
it to the defaults database using the NSUserDefaults class.

However this value won’t be the same if a user uninstalls and re-installs the app.