ResponsiveScreen

main.dart

import 'package:flutter/material.dart';
void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Show up Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: SetitUp(),
    );
  }
}

class SetitUp extends StatefulWidget {
  @override
  _SetitUpState createState() => _SetitUpState();
}

class _SetitUpState extends State<SetitUp> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[
          Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                Container(
                  height: MediaQuery.of(context).size.height/4,
                  width: MediaQuery.of(context).size.width /1,
                  margin: EdgeInsets.all(10.0),
                  child: Placeholder(),
                ),
                Container(
                  height: MediaQuery.of(context).size.height/1.5,
                  width: MediaQuery.of(context).size.width /1,
                  margin: EdgeInsets.all(10.0),
                  child: Placeholder(),
                ),
              ],
            ),
          )
        ],
      ),
    );
  }
}