asudox

https://adps-project.org/

Yet not great from a privacy perspective. They don't even allow third party email apps.

KDE Plasma just keeps getting better every single week.

So XMPP?

"functions on android"

You can download the website's static files then (html, css, images, etc.) but features such as search won't function if it works by querying some database.

Iirc most browsers have a way to make website's available offline. I know chromium has it, but firefox does not. You'd probably need an extension for that. Or you can download the static files, store them in a directory manually and then open the index.html with firefox. That should work.

Would you be ok with reading wikipedia?

There's this app that is for viewing wikipedia pages both online and offline: https://f-droid.org/packages/org.nsh07.wikireader/

To answer your edit: No. They use different encryption algorithms.

Whatever your goal is, there most likely is no such instance that satisfies your definition of "freedom of speech". You should run your own instance where you have full control. Since most instances wouldn't federate with such an instance, a relatively cheap VPS will do. Even some old computer you may have lying around.

No, of course I don't. I am not as paranoid as Richard Stallman, but I am also not as pronoid as the average human to just use proprietary software when there are similarly functioning open source software. With open source software, you can inspect the code and compile the code that you inspected. This is not true for something like iOS.

And of course, FOSS malware also exists (for example the recent xz data compression program). But guess what? You can find if it is really malware or not because you ultimately can inspect the code and compile the code you inspected. That is also why the malware in xz was found out. Who knows what there is in closed source software you can't inspect the code of. Do you perhaps believe in security through obscurity?

Using open source software is always an advantage. Praise for privacy software should be earned through the ability to verify them, and not granted by default.

I don't know about you but if I don't know what a program that I can't inspect the code of does, I'll just assume the worst case scenario. I can't prove it but you also can't prove that it isn't doing something shady, can you? So what if I am using Private Relay? Apple will know what websites I visit or what I do with my phone as long as I use their proprietary operating system and who knows who they'll give it to. And with this, I am saying it again: Apple's operating systems are no exception to this rule.

Mastodon*

I tried using yunohost and some others but they all sucked. I went with just using the bare podman cli