I\'m building an Android app which for various reasons cannot be listed publicly on the Google Play store.
I have found information about the Google Pla
I would just deploy your app using Google Play "Beta testing and staged rollout":
https://support.google.com/googleplay/android-developer/answer/3131213?hl=en
Your users have to join a Google Group or Google + community that you create so you can limit you audience and make the app non-public on Google Play but still allows your non-public users to update the app via Google Play instead of manual APK installation.
The only downside is that the members of the Google Group or Google + community will only be as private as their Google account provides. So, app users are known to each other but your app will not be public on Google Play.