Side note: have you looked at React Native? (I think) it's great! (https://facebook.github.io/react-native/)
14 karma · joined February 16, 2017
> Note that UDIDs beginning with 32-bits of F are returned by the APIs that provide app-specific advertising identifiers on the device, so if you saw one of those and decided it was "invalid", that was returned because they used a tool which tried to return a UDID but was using the older public APIs to do that from a sandboxed application
It did have a bunch of Fs at the beginning, so that is probably the explanation! Thanks :)