Ok, I just remembered I didn't share what I was using on Android.
6) https://play.google.com/store/apps/details?id=com.simplemobiletools.filemanager (and other apps from this dev)
@TheFuzzStoneDAVx^5, formerly known as DAVDroid, it syncs your contacts, calendar and tasks with Nextcloud instance, great alternative to Google contacts, calendar etc. https://www.davx5.com/
A Mastodon instance for maths people. The kind of people who make \(\pi z^2 \times a\) jokes.
Use \( and \) for inline LaTeX, and \[ and \] for display mode.