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.

I feel like that's gone a bit under reported. Reddit is basically saying that their current apps aren't usable for users who need accessibility features, so they're relaxing rules for apps that have better accessibility features, but those apps can't be "commercial".

So basically they don't want to improve their own apps, and they don't want to allow people who build apps with good accessibility to make any money, which means the only conclusion is that they put literally zero value on users who require those apps. Or, alternatively, they put zero value on developers of those apps, which makes their decision to charge other developers tens of millions of dollars to use the API almost inconceivably hypocritcal.