If you're preparing for high school exams and need to improve your English vocabulary, look no further than 高校受験英単語1800. Developed by YTO, this Android app is free and designed specifically for students who want to learn and memorize English words commonly used in high school exams.

With a self-review quiz engine, this app helps you learn and retain words over the long-term. It also offers a text-to-speech feature and supports both Japanese-English and English-Japanese modes. You can choose the level of words to study based on their usage in exams and track your progress with a graph that displays your learning status.

In addition, you can customize your learning experience by selecting only the words you want to memorize. The app also allows you to register your own words for easy management. Please note that the text-to-speech feature requires installation and may be uninstalled on some devices. Overall, 高校受験英単語1800 is a safe and secure app for students who want to improve their English vocabulary for high school exams.