I want to convert my paid app to a free one with in-app purchase without creating a new app and without taking money from people who have already purchased it.
I am currently thinking about the following: Include the License Verification Library to check if someone has purchased the app. If so, the person gets the free upgrade. My question is if Google also responds with LICENSED if the app has been converted to free and someone installs it the first time (new user, not bought it in the past). In this case, would Google also return LICENSED? Because if not, that way we could filter out the people who bought the app before and offer the in-app purchase to everyone else.
Unfortunately this is not really documented, the most detailed I found is the following:
The application is licensed to the user. The user has purchased the application, or is authorized to download and install the alpha or beta version of the application.
From https://developer.android.com/google/play/licensing/licensing-reference#lvl-summary
I am aware that it is kind of a duplicate of Migrate all users of my paid app to in-app purchase, but in the meantime, hopefully there is a better workaround.