The document discusses the importance of user experience (UX) and user interface (UI) in creating a great mobile app. It states that UX/UI is the difference between an average app and a great app. A great app embraces the principles of the platform it is being designed for, has a custom UX/UI tailored to its goals and features, and engages the user. The document emphasizes that offshore development may miss cultural understanding important for UX/UI, and that Apple in particular has set standards for high-quality user experience with their Human Interface Guidelines.