PlatFormTemplate.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

void main() => runApp(MyApp());

/// this is your APP Main screen configuration
class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        // to change your app color change this

        /// first color is for IOS the second color is for Android
        /*******************--[focus here 🧐]--*******************/
        primaryColor: defaultTargetPlatform == TargetPlatform.iOS
            ? Colors.amber
            : Colors.teal,
      ),
      home: Platform(),
    );
  }
}
class Platform extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          leading: Icon(
            Icons.smartphone,
            size: 24,
          ),
          elevation: 6,
          title: Text('App Title'),
        ),
        body: Padding(
            padding: const EdgeInsets.all(20.0),
            child: defaultTargetPlatform == TargetPlatform.iOS
                ? ios(context)
                : android(context))
    );
  }
}

  Widget android(BuildContext context) {
    return Text('replace with Android button and Switch');
  }

  Widget ios(BuildContext context) {
    return Text('replace with iOS button and switch');
  }