Mobile App Scope Definition Assistance

I’m in the early stages of planning a mobile app, but right now the idea exists only as scattered notes and rough thoughts. I need a seasoned product or UX professional to help me turn those concepts into a clear, complete project brief that developers can actually build from... (Budget: ₹12500 - ₹37500 INR, Jobs: Android, Figma, iPhone, Mobile App Development, Mobile App Testing, Product Management, Project Management, User Research)