Get async response data from Application to Launcher Activity

I'd like to make an initialization request when my app starts up. I then want to use the response in my MainActivity. I don't want to make that request in the Activity and then deal with the Activity lifecycle when the phone gets rotated.

So I was thinking of deriving from Application and making the request there. But what's the best way to send the response data to the my launcher Activity?

Is there a "best practice" solution here?