Yes, I meant that exact kind of push notifications like APNS and GCM. If you have an official app for your own service, you simply implement them on your backen

Yes, I meant that exact kind of push notifications like APNS and GCM. If you have an official app for your own service, you simply implement them on your backend. If you're making a third-party app for something, then yes, it's inconvenient, especially if that something doesn't cooperate. Though some services that have open APIs offer you a form to specify your APNS/GCM credentials.