App that teaches you new words

There are many apps that can help you learn new words and improve your vocabulary. Here are some popular ones:

1. Duolingo: Duolingo is a popular language-learning app that also offers a vocabulary-building feature. It uses gamification and interactive exercises to help you learn new words.
2. Quizlet: Quizlet is a study app that offers flashcards, tests, and study games to help you learn new words. You can create your own sets or search for existing ones.
3. Vocabulary.com: Vocabulary.com is a dedicated vocabulary-building app that offers interactive exercises, quizzes, and games to help you learn new words.
4. Word Hippo: Word Hippo is a word-building app that offers interactive games, quizzes, and exercises to help you learn new words.
5. Lingodeer: Lingodeer is a vocabulary-building app that offers interactive games, quizzes, and exercises to help you learn new words. It also offers a "word of the day" feature.
6. Magoosh: Magoosh is a test-prep app that offers vocabulary-building exercises and quizzes to help you prepare for standardized tests like the SAT and GRE.
7. Babbel: Babbel is a language-learning app that also offers a vocabulary-building feature. It uses interactive exercises and games to help you learn new words.
8. Word Cookies: Word Cookies is a word-building app that offers interactive games and puzzles to help you learn new words.
9. Lingo Blitz: Lingo Blitz is a vocabulary-building app that offers interactive games and quizzes to help you learn new words.
10. Vocabulary Builder: Vocabulary Builder is a simple app that offers flashcards and quizzes to help you learn new words.

These apps are available for both iOS and Android devices, and some of them offer a free version or a trial period before you need to subscribe or pay for a premium version.