Flutter Developer for Cross-Platform App

I'm seeking an experienced Flutter developer who can work on a cross-platform app compatible with iOS, Android, and Web platforms. The opportunity is an ongoing long term commitment. Although the key features were not specified, this role requires creativity, initiative, and the ability to work independently. You may have to implement features like user authentication, push notifications and in-app purchases.

Requirements:
- Expertise in Flutter development
- Proven experience developing for iOS, Android and Web
- Ability to work independently and take initiative
- Understand the importance of user interface and user experience
- Quick turnaround time; I need the project completed ASAP.

Your expertise can shape the features of this app, so I am looking forward to seeing your innovative proposals.