This book is an exploration of User Experience Design (UXD). It helps you learn and understand how to design your applications in order to improve the user experience. The UX principles have been discussed. These are the principles that you should stick to when designing an app in order to improve the user experience. Interaction Design principles have also been explored. These are the principles that are concerned with the design of human-computer systems. You are guided on how to design such systems so that they can be friendly to the users. Before designing any app, whether mobile, web etc, it is good for one to know the requirements of users. The requirements define what the users are expecting from the app, and these can only be obtained through research. The author guides you on the best ways and approaches on how to conduct such a research. You are also guided on how to apply the user experience when designing web applications. The author also guides you on how to apply user experience when designing mobile applications for both Android and iOS. The following topics have been discussed in this book: - UX Principles - Interaction Design Principles- User research- How to Apply User Experience for Websites- How to Apply User Experience for Mobile Apps: iOS/Androi