alt Hacker NewsThis submission appears to be a self-promotional advertisement by the developer, who created a HN account literally an hour ago.
"Please don't use HN primarily for promotion. It's ok to post your own stuff part of the time, but the primary use of the site should be for curiosity." https://news.ycombinator.com/newsguidelines.html
If anything, this should be a Show HN.
Fair, and I should have posted it as a Show HN. It's my app and my essay, and I said so in the thread as soon as it came up. New account because I've read here for years without commenting. Happy for a mod to relabel it.