For UI that should differ slightly on iOS and Android, i.e. on different platforms, there must be a way to detect
You can use Universal Platform package:
https://pub.dev/packages/universal_platform
import 'package:universal_platform/universal_platform.dart';
bool isIos = UniversalPlatform.isIOS;
bool isAndroid = UniversalPlatform.isAndroid;
bool isWeb = UniversalPlatform.isWeb;
print('iOS: $isIos');
print('Android: $isAndroid');
print('Web: $isWeb');