The use of smartphones permeates many facets of contemporary mobility. Smartphones and their downloaded apps enhance connectivity for socializing, entertainment, transactions, networking, sharing ideas and even activism and mobilization. While the device and its apps contribute to the creation of communities and strengthen the sense of belonging, they also generate alienation, exclusion and marginalization. Reflecting on this multi-purpose tool is a way of reflecting on the existence, or even pre-existence, of an established technological, sociopolitical and economic infrastructure in the offline world. This book argues that the use of smartphones, and the constant shift between the online and offline world, has created a link between virtual, social and physical mobilities. However, what happens when a smartphone is absent, lost, broken, switched off or confiscated? Indeed, is this network only virtual? Thus, this book offers an insight into ‘compression’, a concept that is developed to signify this tension between the online and the offline. It allows us to understand how the use of smartphones by migrants and those connected to them generates new modes of mobility. Furthermore, the book allows us to understand how online activities and offline infrastructures interact and lead to this compression.