Web and App Development Specialist Required

I need a skilled web and app developer to build a modern, responsive, and user-friendly application. The project should include a clean and professional design, responsive pages for mobile and desktop, functional navigation, user authentication if required, database integration, and API integration where needed. I am looking for someone who can write clean code, fix bugs, test the application, and deliver a fully working project. Technologies may include HTML, CSS, JavaScript, Firebase, and other suitable technologies. Please provide your previous web or app development work and your estimated price and delivery time.