Joker

Joker is a Japanese learning app that helps you learn vocabulary by chatting with your friends and family.

Like ordinary messaging apps, it supports messaging features such as group chats, emojis, replies, reactions, and more.

Unlike ordinary messaging apps, however, it translates your messages into Japanese before you send or read them. In your chat view, every message appears in Japanese, while your friends and family see every message in their own language.

Because every message is related to you, you can learn Japanese quickly thanks to the self-referencing effect, a proven method for acquiring new vocabulary in a second language.

You can also export your decks to Anki so you can review your saved words in whatever way works best for you.