Common GrapheneOS W:
Secureblue's Trivalent browser looks promising. Currently the only way to install it outside of secureblue is COPR on Fedora, but I'm sure there will soon be packages in the AUR, Gentoo, Nix, etc.
Other good options are Cromite, Thorium and Ungoogled Chromium
Oh that sucks. I haven't used it personally in quite a while, since I switched to the Grafana stack
No, it's not a special "FOSS" version, it's just the official binary distributed through the Guardian Project repo (as I have proven: https://lemmy.dbzer0.com/comment/16230276). If you want a FOSS variant, check out Signal-FOSS or Molly, they also offer a FOSS variant. You can either download it from their custom F-Droid repo, pull the APK from GitHub using Obtainium or get it from Accrescent.
Just make sure to set up UnifiedPush if you want to receive notifications while your Molly database is locked. I recommend the new Sunup UP distributor. I wanted to make a post about it in [email protected], but never got around to do it.
For Mollysocket, there are a few public instances. molly.adminforge.de is one of them. You can also set up your own on Fly.io, check out this repo: https://github.com/pcrockett/mollysocket-fly
Or you can obviously self-host it on any VPS or hardware that you own
Thanks, I mean I used to work as a Java developer before, and I'm quite interested in the Android platform, so I'm familiar with the SDK and build tools, and know how app signatures work
But it's really not that hard to figure out. There are countless guides on the internet, and as I said, Signal even has a quick guide for how to verify the APK signature on the download page
Netdata is exactly what you're looking for. It's basically an all in one monitoring and and alerting suite that collects and analyzes data, and provides a gorgeous web dashboard for you to view.
You can also manually replicate this using Prometheus, Grafana and other tools, but that requires a much bigger effort to set up.
Edit: There's a public demo instance where you can try everything out: https://frankfurt.netdata.rocks/
I hope the companion app will be open source, or the watch will be compatible with Gadgetbridge