This work presents the design, implementation, and evaluation of a learning platform that addresses two main objectives: first it provides and on-line quiz tool for students which can be used as a complementary learning approach to the classroom courses. Secondly, this tool performs a detailed analysis of learners use, considering not only the number of mistakes students have made but also the student temporal use distribution and opinion (obtained by a survey) about the difficulty of the learning contents. All this information is processed and used to provide feedback to the teachers identifying the most difficult contents of the area of study and the students with a low learning performance. We have developed and evaluated this tool in two university degree subjects. The obtained results are promising, showing that students can improve their final grades through its use and that teachers can identify the student learning problems, in order to assess where students may require more support or challenge. In addition, we analyze the impact of different metrics obtained by this tool (academic performance, intensity of study and student proactivity) in the final subject grades.