tldr; Can you identify devices on your network as an iPhone OS device easily? Can you send push notifications to devices identified as using the iPhone OS on your network without a a target app? Is is possible to identify which devices on a network are using the iPhone OS? With this information, is it possible to send push notifications to these devices? From my understanding, your application server will contact APNs, which will contact the users. So, the above would be impossible. Can someone confirm this for me? Thanks, P.S.