Carcel

RedReader has never been monetized. They don't have servers to support and distribute for free on f-droid and the play store. It's a small open source project and an influx of users won't change costs for them. The app acts purely as a reddit client for each user and doesn't need a go between server. They accept donations through Patreon and you can find the link on their GitHub repo.

In the case that reddit eventually cuts off their api access too, they're planning on adding support for Lemmy, HackerNews, Tildes and RSS in a future refactor but that's probably not any time soon.

Looks clean and the screenshots look like it supports multiple libraries. Their demo site won't log in but I might spin it up this weekend and play with it. I still probably don't really have a use case for it. I'm always going to need calibre on the desktop. Ubooquity is another that I tried but still had the same lack of use. One of these days I might want to move to a web based solution but not really there right now.

I set up calibre-web on my home server but didn't use it for very long. I've got my books separated into fiction, nonfiction and technical libraries and calibre-web could only handle one library database. I would have had to run multiple instances to get the different libraries served. I also still had a need to use calibre on my desktop so it was necessary to reimport the database from my desktop into calibre-web to keep things in sync. If you're going to manage everything in the web interface it might work for you. It was just kind of unnecessary for my needs.