You can add your device in the testers group. In order to do that, go to Features -> Purchase Manager -> Testers.
Here you can see how to find the device id.
This feature is used to check the issues before they will be published.
It means that you will be able to read all the issues for free, for ever, and also the issues uploaded in the Paperlit dashboard but not published yet.
You can turn on the "Enable test purchases for Android", if you want to buy a subscription on your android app for testing purpose.