This paper reflects on the joint pilot development and implementation of an international master level online course in Educational Design by three universities from different European countries. The pilot targeted curriculum internationalization and provision of international learning experiences to students with less mobility opportunities through online learning and use of technology. The key focus was on connecting students from different countries by collaborative learning and working on an authentic task in the professional domain of their study - educational media design - via a joint platform and digital media. In small international groups, students collaboratively developed mobile game apps for educational settings. Students enjoyed full freedom in design choices, starting from theories in which they anchored their designs to subject matter and the way they implemented designs in mobile applications. In the eight weeks of online learning and collaboration, students demonstrated their collaborative and digital learning skills and made extensive use of tools and technologies. The pilot provided designers with insights on co-designing and coteaching international technology-enhanced online courses. It demonstrated the potentials and the caveats of designing for virtual mobility.