As a Flutter Developer, your main responsibility is to design, develop, and maintain mobile applications using the Flutter framework. This includes writing clean, efficient, and well-documented code that meets the requirements of the project.

Your primary functions will involve analyzing user requirements, designing and implementing software solutions, testing and debugging code, and collaborating with other team members to ensure the project is delivered on time and within budget.

Some of the key duties of a Flutter Developer may include:

- Developing mobile applications using the Flutter framework, including iOS and Android platforms.
- Writing and maintaining clean, efficient, and well-documented code using Dart and related technologies.
- Analyzing user requirements and designing software solutions to meet those requirements.
- Collaborating with other developers, designers, and stakeholders to ensure the project is delivered on time and within budget.
- Testing and debugging code to ensure it meets quality standards and is free of errors.
- Keeping up-to-date with new technologies and industry trends to ensure the software you develop is cutting-edge and relevant.

In addition to these responsibilities, a Flutter Developer may also be required to participate in code reviews, provide technical support to end-users, and troubleshoot and resolve technical issues as they arise. 
As mobile development is constantly evolving, a Flutter Developer will need to keep up-to-date with the latest trends and best practices in the industry to remain relevant and competitive.