If you're looking for a pre-university math problem-solving app, Razonamiento Matemático Pregun by ALVE is an excellent choice. This free app is designed to help students prepare for their math exams, especially those who are planning to apply to private and state universities.

The app offers a wide range of math problems, including algebra, geometry, trigonometry, and calculus. The problems are organized by topic and level of difficulty, so you can easily find the ones that suit your needs. The app also has a timer feature that allows you to practice solving problems under time pressure, which is a great way to prepare for the actual exam.

The user interface is simple and easy to navigate, making it accessible for students of all ages. The app is regularly updated with new problems and features, ensuring that you have access to the latest resources. Overall, Razonamiento Matemático Pregun is a reliable and effective tool for anyone looking to improve their math skills and ace their exams.