In recent years the world has undergone many transformations. Jobs evolve, transform or even change radically when they don't disappear or when new ones are created. Megacities are developing, and people are regrouping in cities and slowly leaving the countryside. We are moving from humanity to urbanity. This is part of real changes that affect everyone, directly or indirectly: climate change, digital uses, natural resource scarcity, demographics, urbanization. The vast majority of web services are moving toward applications available on smart phones. In search of improved services to the population, we have the prediction that all cities of the 21st century will use app platforms, and transform themselves into a service-oriented society, integrating this new intelligent environment based on the massive use of databases (Big Data), cloud computing, and AI (Artificial Intelligence) techniques. In this context, this book aims to explore the opportunities for digital innovations involving the conception of a Smart City.