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.
Can I ask what stands out with Kavita that audiobookshelf lacks?
Audiobookshelf has very basic support for ebooks but it doesn’t compare to specialised software. Kavita has better management, and it comes with a built-in OPDS server so you can use any ebook app that supports that. I also don’t know if Audiobookshelf can actually be used for ebooks without having it as an audiobook as well, never tried it.
Kavita is for ebooks - it’s not perfect, has some weirdness with series sometimes because of it’s manga heritage.