Help with Flutter

I'm learning how to create my own app to publish to the Apple App Store, and Google Play store using Flutter. I'm looking for someone who can help me re-code the data structure so the app is more efficient.

Some of the problems I'm facing are:
- too many calls to Firebase. Multiple calls are made rather than a single call to save on costs.
- a lot of jank in the app.
- setting up a subscription payment system.

I will be sharing the code via Github and you can create PRs.

Regarding payment, we'll see how much can be done in an hour, and then decide if this is a fair rate for future work.