Hey Product Hunt 👋 I'm Adrian. I built kaku.so because I was learning Japanese as a hobby and kept hitting the same wall - I'd "recognize" a kanji on a flashcard, feel like I knew it, then blank completely when I had to actually write it. Recognition and recall are different skills, and almost every app trains the easy one. So kaku.so does two things. First, it's a genuinely fast Japanese dictionary - look anything up, instantly. Second, anything you look up you can drop straight into a spaced-repetition study queue with one tap. No deck-building like Anki, no curating cards - the dictionary and the study tool are the same thing. And it forces recall: meaning + reading shown, blank canvas, you write the word from memory. FSRS-6 schedules reviews right before you'd forget. It's demanding, but for dedicated learners that's the point - you actually retain what you study instead of fooling yourself. It's free, no ads, no tracking, and I have no plans to ever change that. I'm one person building it after hours while finishing a PhD in an unrelated field, so I'd love feedback -especially what's missing or annoying. What would make a tool like this genuinely useful for your own studying?

kaku.so

Japanese kanji dictionary + handwriting spaced repetition

Japanese kanji dictionary + handwriting spaced repetition