It seems like thre are really only a couple of options, and I haven't found many review or examples that show enough detail to compare them.

Jellyfin has a bookshelf plugin that seems to be able to handle it. Audiobooks look to be accessed through the main client app, and ebooks through a companion app like JellyBook, which also claims to handle audiobooks.

On the other hand, there is Audiobookshelf, which specializes in audiobooks, but also claims to host ebooks. It has a number of client apps, but none that I found mention eBook reading.

I've found a couple of other solutions that seem more specialized. Maybe one of those?

I want to be able to read and listen on an Android device, preferably with a native app. I have a few comics, but mostly interested in books and audiobooks. I already have a Jellyfin server setup.