Sổ tay Tiếng Anh 12 is a free Android application developed by Vinsofts Mobile Team that provides a comprehensive study guide for high school students preparing for the National High School Graduation Exam in Vietnam. The app includes useful features such as a summary of the English 12 curriculum, an evaluation tool to track the user's knowledge, an online quiz feature to help users learn the content faster, and a reminder feature to keep up with study schedules. The app's interface is user-friendly and easy to navigate, making it accessible to all students. Overall, Sổ tay Tiếng Anh 12 is an excellent study tool for high school students looking to achieve high scores on the National High School Graduation Exam.