device + app having a unique UUID has been going on longer than that. 3 years ago uber got popped for this: https://www.theverge.com/2017/4/23/15399438/apple-

device + app having a unique UUID has been going on longer than that. 3 years ago uber got popped for this: https://www.theverge.com/2017/4/23/15399438/apple-uber-app-store-fingerprint-program-tim-cook-travis-kalanick https://www.theverge.com/2017/4/23/15399438/apple-uber-app-s... I can tell you that fingerprinting is still possible today.