Multi-Platform Google Drive Integration App

I need an app developed for both Android and iOS platforms. Users will sign in using their Gmail accounts. Upon signing in, the app will automatically create a folder in the user's Google Drive. Additionally, a Firebase function will be needed to create a Google Sheet within that folder when invoked.

Key Requirements:
- Minimalistic user interface
- Google Drive and Google Sheets integration
- Firebase setup and integration
- Cross-platform development for both Android and iOS

Ideal Skills and Experience:
- Experience with Firebase
- Proficiency in Google APIs
- Mobile app development for both Android and iOS
- Strong UI/UX design skills for creating minimalistic interfaces