Flag Guessing - Built my first App! Getting into (iOS) App Developement

Hey All, I'm really new in the development of (iOS) Apps, I'm currently learning on how to get started in the Flutter framework to get into REAL app development :). Anyway this project is a small Proof of Concept where the goal was to create a educational fun game without any external assets or eyecatchers needed. Its a very simple concept, but it was also very approachable and easy to scope. I would love some feedback on the Flutter design and tips and tricks for app dev. Cheers, Jelle