I am developing an iPhone app that need to display some message on lock screen. I have tried to use local notification or CFUserNotification but neither of them can display the message on top of the lock screen. For CFUserNotification I have tried kCFUserNotificationAlertTopMostKey (refer this similar question) but it still not work. I am not going to hook springboard since my phone is not jailbreak. I have found an app do implement it and I have tested on my none-jailbreak iPhone iOS 6.0, don't know how to implement this. Any help much appreciated.