Công Thức Tiếng Anh - Ngữ Pháp Tiếng Anh is an Android app developed by BkiT Software that serves as a comprehensive guide to English grammar. It offers a range of features, including grammar formula lookup, English learning and translation, and English testing. The app is designed to be used by high school students, college students, and professionals alike and can be accessed anytime and anywhere on a smartphone.

The app includes a variety of features, such as English verb tenses, sentence rewriting formulas, verb conjugation rules, and irregular verb tables. Additionally, the app offers text translation services, making it a one-stop-shop for all your English grammar needs. The user interface is simple and accessible, and the information provided is accurate and relevant. Overall, Công Thức Tiếng Anh - Ngữ Pháp Tiếng Anh is an excellent app for anyone looking to improve their English grammar skills on-the-go.