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

Use this little helper method to keep identifier in Keychain between install/delete sessions of app

-(NSString *)getUniqueDeviceIdentifierAsString
{
    NSString *appName=[[[NSBundle mainBundle] infoDictionary] objectForKey:(NSString*)kCFBundleNameKey];

    NSString *strApplicationUUID = [SSKeychain passwordForService:appName account:@"incoding"];
    if (strApplicationUUID == nil)
    {
        strApplicationUUID  = [[[UIDevice currentDevice] identifierForVendor] UUIDString];
        [SSKeychain setPassword:strApplicationUUID forService:appName account:@"incoding"];
    }

    return strApplicationUUID;
}

Add the SSKeychain library to your project, e.g. via Cocoapods with pod 'SSKeychain'