As in title, preferably open-source, but doesn’t have to, I will start:
KOReader - Amazing reader app, and being able to use the same app across various devices, even non-android ones, is pure bliss. Japanese support is pretty good too, which makes me happy. Though… Sadly no vertical text support :c
Syncthing-fork - Being able to keep a library of books, and some files, and easily keep the shared folder across various devices, is mega comfy. Tachiyomi - Cute manga reader.
NewPipe - Really pleasant youtube client, that i sometimes use to listen to things in the background.
Kaku - An useful Japanese OCR app, that works… quite decently for when I encounter kanji that I do not recognize, and is not text.
EinkBro - A web browser, that on e-ink devices, is quite comfy. Has few… quirks, but works well on e-ink
Revanced, it’s the successor to vanced and just as good. I tried newpipe but I didn’t like that I couldn’t log in among other issues.
DraStic. I like playing older pokemon game roms on it.
Kanji tree, a great way to practice kanji.
Island, let’s me use different accounts on apps that don’t allow account switching. For example, it lets me access both my regular amazon account for kindle and my Japanese account that I use to buy manga and books in Japanese occasionally, without having to log in and out all the time. It basically clones apps and let’s you open the clone version as a separate app, so you can have the same app open twice with different accounts.
AI enlarger. Just an app that does a good job enlarging images. I usually use it for art so idk how good it is for photos, but I imagine it’s pretty good. It does an amazing job with art. Better than most other image enlarging programs or apps I’ve tried, except for one paid one that I tested with the free points you get for signing up, which was still about the same in quality.
Kiwi browser, works like chrome but let’s you use extensions on mobile. I usually prefer Firefox but there are some sites or activities where I really want to be able to use certain extensions and Firefox doesn’t have the ability to use the equivalents on the mobile browser. I think Kiwi provides privacy options that help with chrome’s privacy issues though, but don’t quote me on that.
Oh, I do it a bit differently. I just buy on PC, download azw3, deDRM, then convert to epub with calibre, and yoink onto the devices with syncthing, to read on koreader Also, AI enlarger seems nice, so I will check it out