If you don't mind, can I ask why you use plain JavaScript rather than TypeScript?
The product is truly remarkable, so what technologies used under the hood doesn't matter,
but I think TypeScript is natural choice, especially if you 1) start a project from scratch in 2023, 2) have complex local states like choosing equipment and body parts, and proceeding exercises step by step until completed in a single page, and 3) have complex data structure (like exercises, histories, and seamless connection between locally stored data and remotely stored data used only after registering).
Not the OP, but I still start most of my projects without TypeScript, especially if I'm working on it by myself. I do appreciate TypeScript, and I will happily use it in any bigger project or when I have collaborators. But there's just something that I really enjoy about being able to start a project without any build steps or installing stuff. I love to be able to just jam out some code and open a file in a browser to run it, or rsync it to my server and share it with my friends.
Sure. To be honest, it's mostly because of laziness. I'm more used to plain JS than to TypeScript, so I'm faster this way.
I also always thought TS is a bit too much for small apps like this, but I get that it would make sense to use it if others want to contribute as well.
The product is truly remarkable, so what technologies used under the hood doesn't matter, but I think TypeScript is natural choice, especially if you 1) start a project from scratch in 2023, 2) have complex local states like choosing equipment and body parts, and proceeding exercises step by step until completed in a single page, and 3) have complex data structure (like exercises, histories, and seamless connection between locally stored data and remotely stored data used only after registering).
edit: typo