I don't use a third-party night light thing anymore, since everything I use where I want it (macOS, ipadOS, and Plasma) all have it built in.
Much of my hobby stuff involves text, for which I use either micro or iA Writer, depending on the task. For typesetting, I've been playing with typst, which seeks to offer a replacement for TeX. I really like it overall, even if I wish their markup style were markdown rather than asciiDoc. It has *much* less overhead than TeX at this point, and allows in-document scripting (as well as external packages).
Obsidian is my go-to for note-taking/organization, although LogSeq is good too.
For coding, I generally use VS Code with the telemetry turned off. (Shout out to Sarah Drasner's night owl theme for Code.)
I'm in the process of setting up a backup/file sync setup again. For a time I self-hosted a Nextcloud instance, but its unreliability became too much of a burden. (Nextcloud's, that is, not my server host, which was great.) My tentative plan is to go with a combination of rclone and rsync.net, although I need to make sure I understand how to have rclone do automatic syncing rather than having to run it every time.
yt-dlp for grabbing YouTube videos that I find useful and know I'll go back to (typically how-tos/tutorials, but sometimes good, long informative stuff too).
Discord is my primary social messenger thing; not exactly by choice, but because that's what all the communities I'm currently a part of use. But I'm always looking for good subcultures!