QMax is a free Android app developed by Prepas.org that offers around 1400 multiple-choice questions, divided into nearly 20 chapters, covering the physics and chemistry syllabus of preparatory classes PCSI and MPSI. The app aims to test the pure knowledge of definitions and essential formulas, as well as to develop the reasoning abilities and scientific culture of students. The questions are designed in a concise manner, with the use of maximum diagrams and precise scientific vocabulary. This writing style is also encouraged in exam copies. The app features two modes: learning and revision, with the latter offering a STAR level of difficulty after the completion of the NORMAL level. The app also features original illustrations presenting the physics topics with humor.