[Q] Push notifications other than GCM topic

Hi All,

This question is to Android application developers.

We have integrated GCM for push notification in our Android app. However, when a user force closes / kills the app, the user no longer gets notifications unless he / she opens the app again.

However, I have seen many other apps still delivering notifications even when app is killed / force closed.

Can you recommend any other push notification service which works even when app is killed / force closed?

Regards,

Ravi Mittal