I'm working for the first time on a game for Android using Unity and I need to use Google Cloud Messaging to receive push messages.
I've already done the integration of my Unity project with GCM, using this project, and of now I can receive and read messages sent to my phone while the game is running. However, I want to be able to receive them while the app is closed. Currently, if I send a message and the app is not running, I get an error stating that my app stopped working.
So, in essence, I want to know: what are the steps to handle incoming push messages when my app is closed, display them as a notification in Android and launch my game app when I open such notification? What else should I do outside Unity so my project can handle Android notifications while closed?