I love KOreader for the best in class type setting imho. If an e-reader can run KOreader is a purchasing factor to me for that reason. I read a lot so it matters to me how the text looks.

I tried but the whole process is a miserable experience between the stale blog posts and the dead links…

And then the UX… great project but could use a systems guy used to jailbreaking installations and a UX designer

Edit: for kobo at least

I set up KOReader with a jailbroken Kindle. DammitJeff has a good video introducing the topic. UI is definitely awkward, but it is awesome and pretty "hands off" when set up. It also has built-in support for OPDS so downloads from places like "Project Gutenberg" are a breeze. Also, if you are a homelabber with stuff like Calibre & Calibre Sync, it all works as you'd expect.

KOReader is one of these projects where idea is fantastic, it's impressive that it works, and the result is sufficiently quirky that I couldn't get used to it. UI is cumbersome. On kobo, it feels like it's draining battery much faster than the "regular" kobo OS. When you sync progress to KOSync with WiFi you keep getting these "Connecting to wifi" popups. And on mobile, having to use the internal keyboard feels like using the keyboard on a reader, which I do not want to.

I have it on my Kobo, it's really good ! I use it with Wallabag, I can save articles on my desktop and sync it before leaving for work, really nice.

There's a KOReader plugin that lets you sync your progress to a Storyteller server.

https://github.com/Sirozha1337/storytellersync.koplugin

https://storyteller-platform.dev/

This then allows you seamlessly switch back and forth between your e-reader and listening to the audiobook on your phone with automatic position syncing.

It's a great reader app, but as a reader of Japanese light novels it's sadly not fit for my personal purposes - last I checked vertical text is only possible in a really, _really_ hacky way (using a font that is turned sideways), and dictionary support for Japanese (or, say, Finnish with its complex lemmatization) is lacking behind browser extensions such as Yomitan, or mobile apps like Hoshi Reader that have Yomitan dictionary support.

I don't think KOReader handles fixed-size epubs terribly well too, and most of my manga (usually bought on Rakuten Kobo) comes in that format.

For reading English or native language books on non-Android e-readers it's a godsend.

BookFusion recently introduced a KOReader plugin (no affiliation). Combining that with a Kobo has finally let me break free of the Kindle ecosystem

I use it because it supports opds and old Android versions (I have an old Android eBook reader). I host my books on calibre web and never need to do anything beside opening the opds section on koreader and picking what to read.

Great piece of software. Jailbroken my Kindle when the UI was becoming way too slow, then discovered Rakuyomi [1] and that alone is worth the jump, especially with plugins like SimpleUI to make the UX better

[1] https://github.com/tachibana-shin/rakuyomi