As 21st century teachers, we are well aware of the potential of integrating mobile technology into our classes and courses. There is increasing information about how to put this into practice, but do we actually know how learners use these opportunities and how useful they may be? This interactive workshop looks at a programme of tasks conducted via ‘WhatsApp’, integrated into a series of adult EFL courses. Tasks included drills, Q & A and guessing games.  We will discuss how task type influences participation and type of language produced. Furthermore, we’ll see how learners interacted within the groups outside the tasks, and the consequent implications for group dynamics and learner agency.