200 Câu ôn thi bằng lái xe A1 is a free Android application developed by On thi GPLX. This application is designed to help individuals prepare for and pass their driver's license exams in Vietnam for A1, A2, A3, and A4 categories. The app provides 200 theory questions divided into seven distinct categories, including Concepts and Regulations, Road Signs, Driving Techniques, Vehicle Structure and Repair, Culture and Ethics, 20 Critical Questions, and New Questions.

The app allows users to learn and test their knowledge instantly, explaining each answer in detail and providing tips for each question. It also features random exam simulations based on the structure of the Vietnamese Directorate for Roads of Vietnam's driving test. Users can quickly check their results and find out if they passed or failed the exam. Additionally, users can review the questions they got wrong to learn from their mistakes. The app also provides a list of tips for answering theory questions, which users can refer to if they want to learn and memorize quickly.