A JR mobile developer is a professional who is starting his career in the field of creating applications for mobile devices, such as smartphones and tablets. He is responsible for programming, testing and fixing applications, using tools such as Android Studio, Xcode, Flutter, etc. He is also responsible for ensuring the quality, security, and performance of the code.

A JR mobile developer can do several tasks, such as:

- Develop, test and maintain application code using programming languages such as Java, Kotlin, Swift, Dart, etc.;

- Create and apply visual elements of applications, such as layouts, colors, fonts, images, icons and animations;

- Create and integrate APIs to communicate applications with external services or other system components;

- Use version control tools, such as Git, to manage source code and collaborate with other developers;

- Use automated testing and code quality tools to verify code functionality, coverage and compliance;

- Use mobile development frameworks and libraries, such as Android SDK, iOS SDK, Flutter SDK, React Native, etc., to facilitate development and increase productivity;

- Use agile methodologies, such as Scrum and Kanban, to organize teamwork and deliver value to the customer;

- Learn and apply emerging technologies such as virtual reality, augmented reality, artificial intelligence, etc. to improve user experience in applications.