An experience with the App Inventor in CS0 for the development of the STEM didactics

App Inventor is an online tool for creating applications for mobile devices for the Android operating system. With this tool, it is possible to program applications without the need to learn a programming language, an excellent approximation to be introduced in the development of applications. Consequently, App Inventor has also been effectively used for professional development workshops for K12 teachers, as well as introductory computing courses at the college level. Their experiences report on students' high motivation and sometimes also on higher performance. We adopted App Inventor as the introductory programming language for a CS0 in an introductory course to programming in high school. The results we obtained for both the App Inventor language and the CodeMaster tool were less satisfactory than expected and, in some regards, disappointing. We describe our experience, analyze students' acceptance and discuss some consequences and lessons learnt to App Inventor in pre-university courses.