Some businesses go for a straightforward UX design that focuses on vital functions for a great user experience with fewer resources. Certainly, a cool-looking UI design can encourage users to adopt your app. But a seamless, intuitive, and user-friendly UX is a must to keep them engaged. . The front-end is the native mobile app, the visual and interactive user experience that obtains data from an API, and the back-end or sometimes local data storage.
Link: How Does Mobile App Development Work?