I was actually trying out KOReader (on Android via F-droid) last night and it... looks promising... but better than the Kindle app, really? It doesn't have a dark mode which is basically baseline for me reading at night. Or am I missing something?
E-ink screens usually don't want dark mode, because of the weird way they have to refresh[0]. The effect of that is much more visible with white text on black background compared to the opposite.
There's however a dark mode still if you need it; go to the gear icon, screen, auto warmth and night mode. Tap the mode line to switch it from automatic settings (either on time schedule or coordinates) to manual.
[0]: Basically, E-ink displays have to fully "reset" their screen by repeatedly toggling the pixels on and off, since they can't fully toggle themselves off normally; doing so will leave them with a bit of grey. Because this isn't very friendly on the eyes, most displays usually do this every couple "page changes" (actual pages when reading or moving in a menu.)
I've been reading at night for years on my Kindle, and dark mode works very well. During daytime you don't want to use it.
When you're using a device actually for reading, you don't care about minor defects on the page, just like you wouldn't care about some stain on the page of a paper book when reading it.
Thanks, I must have missed it, so that's the task when I go to bed tonight.
I hate the idea of my book collection being chained to Amazon by DRM, absolutely hate it. This whole DRM mess is one reason I haven't bought a dedicated e-reader.
Though, to be frank, it's not the only one, I spent a jaw dropping amount of money on a really good hardcover copy of The Lord of the Rings recently, and I feel like no ebook will ever come close to the reading experience of that thing. There is something about this immense, weighty, hardcover tome that just commands your attention and I still find that print on good paper causes less eye strain than even the e-ink screens I've used (though they are pretty good).
Yes, I also tried it on Android to see if it's worth jailbreaking my kindle and honestly the UI is a bit of a mess. It takes a lot of tweaks to get a nice looking layout to start with, out of the box it's just tiny text filling the screen with no margin.
It's way better than the built-in Amazon reader app.