Principles In Action is a free iPhone app that brings to life the best-selling book, "Principles: Life and Work" by Ray Dalio. The app combines the complete book text, behind-the-scenes videos, and interactive case studies of the principles of success in action at Bridgewater Associates, Ray Dalio's own company. With this app, users can gain access to Ray Dalio's unconventional principles that have helped him achieve unique success in his personal and business life. The app includes a PrinciplesYou Assessment, daily principles from Ray Dalio, a personality test, and a search function for the entire app content, among others.

The app also features a special section where users can highlight, develop, and record their own favorites and those of other users. Additionally, the app provides extra content from Ray Dalio, such as economic studies and complete articles published on social media. The app is highly recommended by various socio-economic leaders, including Bill Gates, Arianna Huffington, and Marc Benioff, among others. Overall, Principles In Action is an interactive and informative app that helps users apply the principles of success to their personal and professional lives.