flutter-umer/flutter_gemini_app ? reverse-engineered prompt

Build me a simple Flutter app called Gemini App that runs nicely on mobile, web, and desktop.

I want a clean starter screen with a welcoming home page, basic navigation, and a few placeholder areas I can easily expand later, like a main content area, an input section, and somewhere to show results or responses. Make it feel polished enough to open and use right away, with sensible styling, light and dark support if it fits naturally, and all the default Flutter setup working across Android, iPhone, web, Windows, Mac, and Linux.

If you need to, look up the current Flutter docs online and follow the best current practices. Keep the code simple and easy to build on later, since this is just the foundation for a bigger app.