A Mobile Application Development developer designs, develops, tests, and deploys mobile applications for various platforms like Android, iOS, and Windows. They work with programming languages specific to these platforms, such as Java for Android and Swift for iOS. They understand user requirements, plan the app's functionality, create a user-friendly interface, and ensure the app's compatibility with different devices. They also debug to fix errors and regularly update the app for performance improvements. Furthermore, they integrate the app with backend services for data synchronization and work closely with UX designers and testers for an optimal user experience.