This book is an accessible introduction to Progressive Web Apps (PWAs) and how they are revolutionizing the mobile web. This book will explain what PWAs are and how they compare to hybrid and native apps. It will show how they work, what benefits they bring, and will also outline situations in which a PWA might not make sense. Topics covered include: Using HTTPS Service Worksers Cache Storage API Using the Web App Manifest Common design patterns Performance and accessibility Several real-world case studies are featured thoughout. Additionally, the final chapter will show you how to convert an existing application into a PWA