Am new to Apple Push Notification services in iPhone app. I have learned these tutorials and apple document,
APNS does not tell you if a message is successfully delivered. The closest you can get is pull its Feedback Service to see if your app is uninstalled from a device. Check out this SO post for an idea how: PHP technique to query the APNs Feedback Server
What you can do is have your iOS app record something whenever a push notification arrives with
application:didReceiveRemoteNotification but that only works if your app is running in the foreground.