The app has been published on F-Droid!
https://f-droid.org/en/packages/com.anthonyla.paperize/
I am aware that the app has been taken off the play store -- my developer account has been permanently terminated. No reason is given other than "high risk behavior," and they are refusing to give any details in the appeal. I won't be able to publish to the Play store from now on, so F-Droid/F-Droid adjacent and GitHub will be the only source of this app from now on. Sorry for the inconvenience!