In this chapter we consider the paradoxical nature of the Janus-faced smartphone. Drawing inspiration from Mick and Fournier’s seminal paper (1998), ‘The Paradoxes of Technology’, we address how the smartification of the mobile phone is freighted and fraught with paradoxical implications. In the course of our musing, we present a ‘thumbs up’ and ‘thumbs down’ review of contemporary thumb culture illustrating how the smartphone (1) facilitates an extended and a passive self, (2) is both a help and a hindrance to health and wellbeing, (3) creates and limits new opportunities for social movements, and (4) frees and tethers its keepers.