push silent notification through GCM to Android/IOS
<p>I'm seeking to send an state update to an application, which can (or not), be silent.</p>

<p>For example, if the user gets a new message from one of their friends I want to send such message and be able to display an alert with sound.</p>

<p>But in the silent case, I want the user not to notice such notification. it must be gathered by the application; for example if my user has two devices and he changes his name in one of them, I want to send the other device (which is sleeping) a silent name update, that should trigger a change (be dispatched to the application) in background.</p>

<p>According to what I've read this is actually possible, but I'm quite confused regarding to how it actually is, or how it should be done, and there are some contradictions at times. As a backend developer I can do anything but I need to make sure that it works for the frontend guys.</p>

<p>Here some relevant topics:</p>

<p><a href="https://stackoverflow.com/questions/35187548/silent-background-push-on-ios-and-android">Silent background push on iOS and Android</a></p>

<p><a href="https://stackoverflow.com/questions/5131861/push-notifications-without-alert">Push Notifications without alert</a></p>

<p><a href="https://stackoverflow.com/questions/25939606/iphone-push-notification-without-alert">iPhone push notification without alert</a></p>

<p><a href="https://stackoverflow.com/questions/15671140/android-silent-push">Android Silent Push</a></p>