https://element.io/ Not centralised & doesn't require a phone number, two things I dislike about Signal/Telegram.

I found working through the new edition of the "Project Oberon" book on a cheap $99.95 board extremely educational. It could be a good starting point for personal projects. Might require some appetite for risk for commercial use though.

They can now take air superiority over the South China Sea and if any of the other countries with claims to the area shoot the drone down, they're the bad guys for causing an ecological disaster.

This exists ( https://www.state.gov/document... ). A sizeable volume of requests are processed every year. However, some US judges don't want to use the official channels, I suspect because they are egotistical enough to think that their writ applies outside US territory. I don't mean to knock Americans, this is just human nature. An Irish policeman recently was recently in the papers for cooperation with the FBI to get Facebook to do something that could have been done much quicker by just asking the company's Irish branch office.

Org-mode in Emacs, with a private git server. I don't really try to do anything productive on a phone/tablet, but there is MobileOrg if you do, not sure how it works. Org-mode can do much, much more than take notes mind you.

I liked Coclarity's product, Goshido, when I tried it. Obviously YMMV.

Full disclosure: I don't work for Coclarity, but I do know the owner.