Does anyone have some recommendations for good epub readers on android, preferably with TTS as an option for audio books? Currently using Lithium with network access disabled and other than it not having any form of TTS and not being updated for almost a year it seems great.
Oh, tangential observation, why are so many epub readers not updating anymore?
I like Librera FD (the free, full featured F-Droid release). I also used Readera in the past. Koreader is best for e-ink devices.
I’m not into audiobooks and don’t know if any of my recommendations support that.
The average ebook reader is using an Amazon, Apple, Kobo, etc. device and buying books from their device’s integrated store. People generally don’t bother with managing their own media libraries, even if doing so would protect them from getting locked into a tech product’s ecosystem.
I’ve tried Librera and found it be very clunky compared to Yomu where i came from on iOS and Lithium now on Graphene.
As to managingy own library, yeah, I’m looking to use epubs and have a TTS system read them out for me if I can find a decent/working one.
Found Book Story on FDroid today and it looks like it’s well on its way to being my reader of choice, FOSS, Material3 (so not a mess to look at or navigate), actively updating, etc. It is a little rough right now but the main missing features I’m interested in are in the ToDo list, albeit frozen. This looks like a project to keep an eye on if you like reading ebooks on your phone.
Found Moon+ Reader to be quite good. Don’t know about audiobooks or TTS though.
I know I’m late to the party but SumatraPDF looks like the best eBook Reader I’ve been able to find.
I just read this review:
MuPDF Viewer!
Great for epub and pdf files.
ReadEra is nice, supports various file formats also.
I just noticed you’re only looking for Android EPUB Reader Apps and not for Windows. Sorry! 
I felt so bad for suggesting a Windows App that I spent all night searching for the best open source EPUB Android reader and believe me, it’s not easy!
And as you said, many aren’t being updated anymore… I came across many that looked great but were no longer being maintained…
I’ll reply as soon as I find something!
Until we find something suitable for you, have you thought about Netguard to secure your Android device up for now? Netguard is an open source App for Android and it’s great and it’s cheap.
Books Story like I mentioned above has been great, and Lithium did recently get an update as well. Acclorite (the dev for Book’s Story) plans to be adding a ton of features over time and just recently did a big rewrite of all their code to make it easier to add and change things going forward.
As to NetGuard, I find RethinkDNS to be a better option due to the built in filter lists and wireguard support.
Hey Rasta bro, I’ve spent literally the last few hours trying to find an EPUB Android Open Source Reader for you and I just can’t find something that matches your criteria of being open source AND also being currently maintaining/receiving good support and updates.
Sorry Rhasta! I hate making promises and then not falling through on them!
I swear man, I must have researched 15+ different Android EPUB Reader Apps!
This is the best I could find so far. It’s open source and it;s still being actively maintained:
To give you an idea of how many EPUB Android Readers that I looked at that were highly recommended but have now been taken down and are no longer maintained:
https://play.google.com/store/apps/details?id=com.github.axet.bookreader
https://play.google.com/store/apps/details?id=com.quaap.bookymcbookface
https://play.google.com/store/apps/details?id=net.zorgblub.typhon
https://play.google.com/store/apps/details?id=org.sufficientlysecure.viewer
https://play.google.com/store/apps/details?id=org.sufficientlysecure.viewer
There are more that I came across but I don’t want to bore everyone by listing them here!