YELLO is a mobile application that offers all the lessons of the terminale class in audio file; the baccalaureate exams from the year 2000 to the present day and the various books on the program in PDF and audio files. It offers all the lessons for the final year class (Philosophy, History, Geography, French, Mathematics, etc.) in audio file to facilitate revision. Mobile devices can be very useful, for uses ranging from simple note taking during lessons to more advanced applications. YELLO thus offers educational possibilities that we cannot commonly have with other learning tools. In particular, it allows students to access content anywhere and anytime, and to experience new learning situations in different places and not just at school.