Mobile app for the USA market - MVP

Develop a mobile app for a startup in the Health and Fitness category. The plan is to start with an MVP and add more features later. Overall, the feature roadmap is pretty well defined at this point but it will be adjusted based on user feedback.I will share more details about the app and its value proposition during the interview.For tech stack, I was thinking Flutter frontend and Firebase backend but open to your input and suggestions.Experience with Chatgpt API integration, or other kinds of AI integrations, would be a plus.