Jeremy Wilken's book, "Ionic in Action," published by Manning, provides a comprehensive guide to using the Ionic framework, which is particularly suited for developers familiar with Node/AngularJS. Wilken, who transitioned from a background in the arts to a career in front-end engineering, started using Ionic in early 2014 due to its compatibility with his team's skill set and the rapid prototyping it allowed compared to native tools. The book, which is available in an early access version, aims to empower developers to build mobile apps efficiently by leveraging their existing skills. It includes practical examples through three developed apps: a resort guest app, a bitcoin market app, and a weather app, each showcasing various Ionic components and providing a near-complete solution ready for deployment with some reader-driven enhancements. The book also covers advanced topics, such as differentiating app interfaces across platforms like iOS and Android, using Ionic components for seamless adaptation, and emphasizes the importance of testing in software development, offering insights and examples for setting up tests.