Develop and optimization flutterflow app

I have an application about Accessible Tourism developed in Flutterflow that currently has ui/ux issues.

I organized in notion a list of the main ui/ux tasks, including points such as dark mode consistency, component review, and creation of new modals.

The app is already live on the App Store (iOS). For Android, Google Play required at least 14 days of user testing. That period has already passed, but I have not submitted it for publication yet.

The previous developer did not deliver what was agreed, which significantly delayed the project.

I also now have a design system defined, but it is not properly applied in FlutterFlow yet, since it was created after the app was already in development.

Given this, I would like to understand if you could help me with this project, and especially your technical opinion: in this case, do you think it makes more sense to continue working on the current FlutterFlow base or to rebuild the app from scratch?

Notion link: https://www.notion.so/Documenta-o-Geral-Aplicativo-2fc0a8b42c7a8017a0a6eb8d345857ef?source=copy_link

App in Apple Store: https://apps.apple.com/br/app/passaporte-acess%C3%ADvel/id6745103908

Link web: https://passaporte-acessivel-app.flutterflow.app/onboarding

Do you believe you can help me with this? What would be your estimated timeline and cost for this work?

Category: IT & Programming Subcategory: Apps programming. Android, iOS and others What is the scope of the project?: Create a new app