This app consists of two parts. And, you can also select between 2 languages, such as English or 日本語, at the bottom of the page.

On the one part where you could practice Japanese letters selecting [Letter list] and Japanese words selecting [Word list]. All of which relates to words used in Eight Queens game. On the other part where you could play Eight Queens game.

Lastly, I would like you to feel like having a bit of Japanese letters and Eight Queens game up your Apple Watch, as the saying goes, "have something up one's sleeve."