This volume is based on an ERASMUS+ project that ran from 2017 to 2020. It aimed at empowering both prospective teachers and teacher educators to actively become agents of their own continuing professional development. It further intended to cooperatively establish a culture of self-reflection, as well as an intercultural network of professionals who creatively use mobile technologies and innovative ways of teaching and learning in the field of foreign language teaching. All contributions were provided by our partners from Germany, Sweden, Spain, and the UK and give an excellent insight into all the manifold aspects dealt with in this project - including voices of participating students.