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
StreetComplete. It’s an easy way to improve openstreetmap wherever you are. https://f-droid.org/en/packages/de.westnordost.streetcomplete/
Your link is broken, the address it leads to is “url”. [link text](https://f-droid.org/en/packages/de.westnordost.streetcomplete/) would be the correct way.
Merlin - It’s a birding app and can identify birds by picture or by their song.
Oh how cool though, I didn’t realize they had anything out there that can identify birds by song like that. Is it pretty accurate?
NetGuard Pro - Allows you to see and control traffic from all apps, so you can prevent data flows to 3rd party hosts like the ones from Google or Facebook. The pro edition is paid and necessary, but it’s all open source, just not gratis
Aegis Authenticator - open source 2FA authenticator
LibreTube - alternative, privacy-respecting, open source YouTube frontend using the Piped API
Not quite wrapping my head around aegis, what’s the point? It seems like a password manager, more or less
Is netguard still maintained? I seem to recall seeing the developer freeze development maybe a year or two ago? Hopefully I’m wrong.
Moshidon for a Mastodon client
Droid-ify as a much better fdroid client
Another Notes to plan world domination
InnerTune as a great YouTube music ripping app
Feeder for RSS feeds
Xtra as a Twitch client
Tutanota for email/contacts/calendar
Fennec (or Mull) for a demozilla’d stable Firefox with all tracking/analytics/proprietary stuff removed
Mostly stock AOSP apps from my custom GrapheneOS rom.
Every one of those apps are on fdroid, except the built in stock apps obviously