Create a UDID for the Device

gistfile1.m

/* 
 UNIQUE IDENTIFIER
 */
+ (NSString*) deviceIdentifier {
    
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSString *deviceId = [defaults objectForKey:DEVICE_ID_KEY];
    if (!deviceId) {
        //Create unique ID
        CFUUIDRef newUniqueId = CFUUIDCreate(kCFAllocatorDefault);
        CFStringRef newUniqueIdString = CFUUIDCreateString(kCFAllocatorDefault, newUniqueId);
        deviceId = [NSString stringWithFormat:@"%@",(NSString *)newUniqueIdString];
        CFRelease(newUniqueId);
        CFRelease(newUniqueIdString);
        //deviceId = [self getMacAddress];
        
        //Save it
        [defaults setObject:deviceId forKey:DEVICE_ID_KEY];
        [defaults synchronize];
    }
    
    return deviceId;
}