This book describes and compares three co-creation projects that were conducted in two European cities as part of a larger EU-funded innovation project called Mobile Age. This chapter introduces Mobile Age and presents the project’s framework and methodology for co-creating digital public services. Part of the framework are seven streams of activity that need to be considered. These streams of activity are not sequential but run in parallel and inform each other: (1) governing and managing a co-creation process; (2) continuous recruitment and engagement of stakeholders; (3) co-creating a service concept; (4) working with (open) (government) data; (5) co-creating software; (6) evaluating the co-creation process and its results; and (7) exploiting and disseminating the co-created service. All three co-creation projects featured in this book are described along those streams of activity. In addition, for each project its specific problem focus, target audiences, value propositions and resources are provided.