The 英検4級の英単語570 - 英語問題学習アプリ is an educational and reference app designed to help users improve their English vocabulary skills. Developed by Taro Horiguchi, this app focuses on the concept of "mastering words to master 英検®," a popular English proficiency test in Japan.

Understanding that vocabulary is a key component of any language proficiency test, this app includes 570 highly important words that frequently appear in the 英検®4級 exam. The app follows a study and test cycle, allowing users to study the words and then assess their understanding through quizzes. By repeating this cycle, users can deepen their comprehension of the vocabulary.

It's important to note that this app is not officially endorsed or recommended by the Japan English Test Association, the organization behind the 英検® exam.

Please note that the app is only available for iPhone users and is free to download.