AyushShende2679/splitmate ? reverse-engineered prompt

Build me a Flutter app called SplitMate that helps people track personal expenses and split group bills with friends, family, or roommates. I want it to feel simple and modern, with a clean home screen, light and dark mode, and easy ways to add expenses quickly, including tiny payments like ₹1 to ₹10. It should support Google sign in, save data securely with Firebase, and work offline too so users can keep logging expenses even without internet, then sync everything automatically when they are back online.

Please also include monthly spending reports that can be turned into a PDF and shared, basic charts or summaries for quick insights, and a thoughtful optional parental monitoring feature that only works with permission. Make it run well on Android, iPhone, and web, and use a polished, friendly UI that feels intuitive for everyday use. If you need to check current docs or best practices, look them up online.