Delve into Flutter's UI framework to build high-quality Android apps, from creating contact profiles to enhancing them with themes and API integration, culminating in app publication.

Flutter is Google’s mobile UI framework used for crafting high-quality native interfaces on iOS and Android. This course focuses on building applications for the Android platform.

You’ll start by exploring the intricacies of Flutter and work your way up to implementing a contact profile page for an Android address book.

In the latter half of the course, you’ll learn to work with Flutter themes to spruce up the contact profile app you created. To round out your Flutter experience, you’ll also practice fetching data from a remote Application Programming Interface (API).

You’ll put into practice what you learn using live coding environments embedded within the course. By the time you’re done, you’ll be ready to create your own Android app and publish it to the Google Play Store.

Salahaddin Mohammed

I completed the course "Beginning Flutter: Android Mobile App Development" at the Educative platform. I have easily understood the course because of your great explanation. I want to thank you really!

Thank you letter from a student.

Beginning Flutter: Android Mobile App Development

In this lesson, we'll dive into the Dart code for the Hello Flutter app. 

As discussed in the last lesson, the *Educative* platform provides the in-built environment to create a Flutter project. So, we are all set to start some coding! 

Let's dive in and start coding the Hello Flutter app right away.

# Hello Flutter App
Our app name is `HelloFlutterApp`. This extends a Flutter widget `StatelessWidget`. We'll go over types of widgets in later lessons.

```
class HelloFlutterApp extends StatelessWidget {
  ...
}
```


> Flutter widgets implement material design. 

# Material design

[Material design](https://en.wikipedia.org/wiki/Material_Design) is the design language developed by Google to better unite fundamental design principles with technology.

Material design has three core principles: 

* On-screen elements are the metaphor of the off-screen elements. User experience enhances when UI appears similar to real-world objects.  

* The material design puts emphasis on having a design that makes sense, is easy to follow (bold colors, headlines), and is uncluttered (negative space).

* Material design uses motion to provide feedback. When you hold down on an icon, it pops out a bit to tell you that it's ready to be moved.



# Using material design

To use material design, you need to import the [`material.dart` package](https://api.flutter.dev/flutter/material/material-library.html) to access `StatelessWidget` and other material widgets.

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

# Building the interface

Next, we need to tell the `HelloFlutterApp` widget how to build itself inside the `build(BuildContext context)` method.

```
class HelloFlutterApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    ...
  }
}
```

## The `MaterialApp` widget

The MaterialApp widget requires `home` property to be specified. The `home` property declares which widget will be displayed first when the app launches. 

```
MaterialApp(
      home: //,
)
```

## The `Center` widget

We want to show the greeting message in the center of the screen. So, we use the `Center` widget as `home`. Its child is the `Text` widget.

```
Center(
        child: Text("Hello Flutter !"),
      ),
```

## The `build()` method

At this point, the `build()` method will return the `MaterialApp` widget with a centered text string in it. `HelloFlutterApp` class will look like below:

```
class HelloFlutterApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Center(
        child: Text("Hello Flutter !"),
      ),
    );
  }
}
``` 

In this lesson, the structure of the Flutter project will be covered and discussed in detail.

Introduction

Hello Flutter !

Build your Contact Profile Page

Flutter Themes

MovieApp: Fetching Data from REST API

Where to Go from Here

Appendix: Installation & Setting up Flutter (Optional)

Flutter Project Structure

Hello Flutter App

Material design