Flutter App Upgrade & Play Store Upload

I'm seeking a skilled Flutter developer to upgrade my app. The upgrade includes adding In-app purchases functionality and overall enhancements to the app. Ultimately, this upgraded version of the app needs to be uploaded to the Play Store.

Ideal skills and experience:
- Proficient in Flutter
- Experience with integrating In-app purchases
- Knowledgeable in UI/UX improvements and Performance enhancements
- Prior experience with uploading apps to Play Store is a plus.

Please provide relevant examples of your previous work in Flutter.