I'm working on a few things, but the one that's gaining the most traction right now in terms of users is kyoubenkyou

https://www.kyoubenkyou.com/

In short, it's a few things:

- JA->EN dictionary

- hiragana / katakana / time reading / number reading quizzers

- learn kanji with FSRS, anki-style

- vocab quizzer

- the coolest feature (imo) is a "reader": upload Japanese texts (light novels, children's books, etc), then translate them to your native language to practice your reading comprehension. Select text anywhere on the page (with your cursor) to instantly do a dictionary lookup. A LLM evaluates your translation accuracy (0..100%) and suggests other possible interpretations.

It's all elixir+liveview+postgres+pgroonga (though there are times when I would like to have SolidJS).

I've been considering open-sourcing it due to lack of commercial success, but might try an ad-based approach first.