In the 2010s, as messaging apps replaced SMS to become the main communication technologies for millions of people around the world, WhatsApp rose above its rivals to become a global communication platform. In this book, Amelia Johns, Ariadna Matamoros-Fernandez and Emma Baulch provide a comprehensive account of WhatsApp's global growth. They begin with its emergence from a messaging app to its purchase by Meta in 2014, which, they argue, transformed WhatsApp from a simple, 'gimmickless' app into a global communication platform. Understanding this development can shed light on the current status of WhatsApp in relation to rivals, the trajectory of Meta's industrial development, and how global digital economies and social media landscapes are evolving with the rise of 'Superapps'. This book explores how WhatsApp's unique characteristics mediate new kinds of social and commercial transactions, how they pose new opportunities and challenges for platform regulation, civic participation and democracy, and how they give rise to new kinds of digital literacy as WhatsApp becomes integrated into everyday digital cultures across the globe. Accessibly written, this book is an essential resource for students and scholars of digital media, cultural studies, and media and communications, as well as anyone interested in the emergence and growth of WhatsApp.