The job duties of an entry-level mobile application developer focus on app creation for mobile devices that run on iOS and Android operating systems. Your responsibilities in this career usually require you to work on programming for both smartphone and tablet environments. You program software to be used on a mobile device and then test and debug the application. An entry-level developer often works on one aspect of an app development project. There are different fields within mobile app developments. You can find jobs in game development, utility app development, or commercial app development. While many of these skills are the same, most developers have a specialization.