I just realized this post is from last year..
shiham
Gitea! https://gitea.com/
Been using self hosted for about 2 years now, it's light weight and low maintenance!
Yes to the last bit of edit.
No, because federated.
if websites you need start using it, then yes.
If it supports Oauth K-9 Mail probably works.
I'm not sure about the first
But as much as I hate Samsung and Facebook for doing this, I don't think they actually do anything.
They're basics place holder apps with version number set to a low number, so when you update all apps from play store these gets 'updated' and installs the functional app.
You don't need same app on both for phone to use matrix, there are multiple apps that can communicate over matrix, some may not be available on both iOS and Android.
But if you were to use matrix, I'd recommend using Element which just happens to be available on iOS and Android.
Linux just gave me the foundation...
roadmap.sh