[mpakes]

Such a thing has existed since iOS 2.0 (CFUUIDCreate [1]), and Apple's updated docs on UDID specifically recommend using CFUUIDCreate. The problem is that an application-specific UUID doesn't address all current use cases for UDID. Specifically, ad networks that support Cost-Per Install (CPI) need to use an identifier that crosses the application boundary.

[1] https://developer.apple.com/library/mac/#documentation/CoreF...

[mikeash]

Perhaps I misunderstood, but CFUUIDCreate doesn't create an application-specific UUID, it just creates a new, arbitrary, UUID that isn't tied to anything. You could then use that to build your own app-specific UUID mechanism, but the API won't do it for you.

[mpakes]

Good point; I may have replied too hastily.

It's relatively straightforward to use CFUUIDCreate as a building block for an application-specific UUID, but you're correct in stating that the API itself simply returns a new, pseudorandom UUID.