Build an existing app in flutter, have automated export of data to the cloud and including change from KML files to JSON

I have an existing app that needs to be re written in Flutter see attached. There are 4 minor bugs to be resolved and the saved objects need to be prepared as JSON rather than KML. The app will need to be able to upload the test results to a cloud data base (to be developed). Users will need to be able to self register via an admin.