I am looking for some way to disallow users from my app (ban them for not following rules for example). If I can detect some kind of phone id that is constant, this would be perfect since I can just check for it at the start of app and if it matches a "banned" id, not allow the app to proceed. I looked into identifierForVendor from UIDevice class but it appears that this is not constant? It looks like if the user of app deletes all my apps and reinstalls, the restriction would go away.
Basically I am just looking for an id that would be constant, no matter if a user deletes my apps or not. Something to recognize a user by (well a phone by). I am supporting iOS7 and above.