Always get a unique device id in iOS 7

Question

Our iOS application is for specific users. So, we used device unique identifier for user identification. This approach works fine till iOS 6, because we are

Answer 1

Are there additional apps from the same vendor installed on iOS7 devices? According to the docs:

The value in this property remains the same while the app (or another app from the same vendor) is installed on the iOS device. The value changes when the user deletes all of that vendor’s apps from the device and subsequently reinstalls one or more of them. The value can also when installing test builds using Xcode or when installing an app on a device using ad-hoc distribution. Therefore, if your app stores the value of this property anywhere, you should gracefully handle situations where the identifier changes.

Do you provide the app via the AppStore? If not:

If the app was not installed from the app store (such as when the app is still in development), the vendor is determined based on the app’s bundle ID. The bundle ID is assumed to be in reverse-DNS format, and the first two components are used to generate a vendor ID. For example, com.example.app1 and com.example.app2 would appear to have the same vendor ID.