In this article a new authorial EduPython application is presented. It is an online tool that supports the teaching of physics using a problem-solving method. It gives the teacher an opportunity to collect data that students send using their smartphones. The application uses the data to produce a collective answer of all the students which gives the feedback. On the basis of the feedback, students can find out how close they are to finding the correct answer. A teacher, on the other hand, can run the course of a lesson more precisely. Furthermore, EduPython lets the teacher run a lesson on the basis of computer simulations of real experiments, including those which are impossible to carry out in a regular school environment. In the paper, an example of interactive lesson at the level of secondary education using EduPython tool is presented.