Six short reads — the approach, how to play, where the data comes from, the full source list, the privacy policy, and how to get support.
Why this app exists, who it's for, and how it differs from other Japanese learning tools.
The tap / hold loop, what's inside the back face, and how the Challenge Box works.
How the vocabulary, kanji, and grammar lists were built — methodology, in plain English.
Every dataset behind the app, with size, license, and what we use it for.
What we collect (nothing) and what stays on your device.
Common questions, bug reports, and how to reach me.