The Sinch Pushkit VoIP iOS Sample Code demonstrates how to learn to use the PuskKit framework to run it from the Sinch Voice API. Push works
without the user knowing about it and Apple promises to deliver these push notifications as high priority.
When it comes to mobile computing most organizations are relying on applications that are running on a number of devices that remotely access data via an API. The folks at Usablenet are leveraging RESTful APIs to make the case for the exact opposite scenario.