Cross-Platform Flutter App Development

I'm seeking an experienced Flutter developer to build a cross-platform app for iOS, Android, and Web.

Essential features include:
- User Authentication
- Push Notifications
- In-app Purchases

Ideal Skills and Experience:
- Proficiency in Flutter and Dart
- Experience with cross-platform app development
- Strong background in implementing user authentication and push notifications
- Familiarity with in-app purchase integration

Please provide examples of similar work done.