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Flutter App Development: A Complete Guide

Flutter App Development
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Flutter is the second most popular cross-platform mobile framework choice for most developers, backing over 100,000 applications since it was launched, according to Statista.

It was coined in 2017 by Google and is open-source. Its ability to create high-quality and fast-performance applications spanning mobile operating systems – Android and iOS – and other features make it a good choice for many developers.

If you are a decision-maker or an entrepreneur, you can use Flutter to achieve high-quality apps for your business at a pocket-friendly price.

If you’ve considered using Flutter, now is a good time to start. In this article, you will learn how Flutter can help you as a developer and how you can use it to empower your products.

What is Flutter?

Flutter is an open-source framework, occasionally called Software Development Kit (SDK), used for building natively compiled cross-platform applications. You can create mobile, web, and Mac solutions from a single codebase.

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Flutter comprises a framework – a set of reusable user interface components (buttons, forms, sliders, etc.) that you may customize as per your needs, and an SDK – a set of tools including frameworks, libraries, and APIs to aid you in developing fully functional applications.

The Flutter framework is written in the Dart programming language, developed by Google, which heavily focuses on the front end.

Why Do You Need Flutter as a Developer?

Unlike maintaining numerous libraries in Java, JavaScript, Swift for Android, and iOS, all for a single application in multiple operating systems (OS), Flutter encircles all your code in one language, and this structure suits cross-development. Of course, managing code for all your applications at one point saves your developer time.

You can use Flutter’s split-second compiling for instant previews. In this case, you can use Flutter’s hot reload functionality feature to look at code changes and adjust accordingly. You can also access Flutter’s source code and modify it to suit your needs making it easy to code and build apps.

What Makes Flutter Unique?

Flutter has a reputation for saving time for app development processes and costs and helps build apps with user-interactive designs and smooth animations.

If you want to learn Flutter, having a solid familiarity with it would be best so that when you do, you can skip the introduction bits and start learning. Here’s a breakdown of its key features:

  1. Cross-platform support: Flutter develops natively compiled applications from a single mobile, web, and desktop code base. In mobile app development, you do not need to write code for multiple apps, say for Android and iOS, saving you time and the headache of developing numerous applications. This cuts the cost too.
  2. Available SDK and native features: Flutter utilizes its native code, platform APIs, and third-party integrations, simplifying the development procedures and, thus, a good developer experience.
  3. Widgets: Flutter has numerous specialized designs that you can customize according to your needs.
  4. Hot reload: When you make changes in your code, this feature allows for tracking your code changes instantly. Flutter indicates updates that are apparent to the app itself.
  5. Open source: Flutter is entirely free to use and open source. You can integrate various packages and third-party libraries in your app, be it videos, chats, advertisements, or other features.

Next, we will explore some of the advantages of using Flutter.

Advantages of Using Flutter

#1. Business Logic UI on All Platforms

Flutter provides the best way to share code between platforms. In this case, you do not need to build platform-specific components to render UI; you only need the canvas to draw on.

#2. Reduced Code Development Time


If you are working on a mid-size android application, it takes up to 40 seconds to adjust a layout feature. The inbuilt hot reload feature makes your changes almost instant.

#3. Increased Time to Market Speed

If you are using Flutter for your app development, it takes you half the workforce needed instead of working out two separate apps, say on Android and iOS.

This saves you time because you do not have to write platform-specific code, yet you will still achieve the desired visual across all your platforms.

#4. Similarity to Native App Development

Today’s technology approach to building digital products prioritizes the user experience (UX). With Flutter, you can create better user interface (UI) animations; Flutter is built directly into machine code, eliminating performance bugs in the clarification process.

#5. Rapid App Growth


You can access many widgets for your development hence faster development and growth. If you also eye the market for your application, you can use Flutter to create hang-free apps. Users like it, and this experience excites them to share your product growing its market scope.

#6. Minimalistic Design Features

If you want to use distinct widgets for your application, Flutter allows you to create new ones, and either use them independently or combine them with existing ones. This approach is vital to providing the greatest user-friendly designs.

Drawbacks of Using Flutter

#1. Libraries

As a developer, you need third-party libraries for certain functionalities in your software. While third-party libraries are free, open-source, and readily available, this is not the case with Flutter.

It is a new framework and is still evolving and improving; you may need to wait for some tolls, build your own, or in a worse case, find another option for long-term development.

#2. Integration

Integrating Flutter with continuous integration (CI) platforms can be challenging, unlike native Android and iOS. You may need to create and maintain custom scripts for building, testing, and deploying Flutter apps in the CI processes.

#3. Weak iOS Features Support

Google backs Flutter, leaving iOS support suffering. For instance, an application on iOS deletes all EXIF data on taking pictures while on Apple devices. As a result, your photo gets an incorrect orientation, location, and gamma. When you look at unique iOS accessibility features like voiceover, guided access, captioning, and audio description are not well supported in Flutter.

How to Make Flutter App

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You have already spent significant time being theoretical; let’s get tactical and work out a simple application to help you understand how to build using Flutter.

Installing Flutter

You will need an integrated development environment (IDE) for the development, creation, and testing of your software quickly. You can choose between:

  1. VS Code – Has all the desired qualities in an IDE, including light and fast. VS Code has been a top developer choice; you can focus on it.
  2. Android Studio – To start with Android Studio, you only need to set up its SDK. Install the Flutter and Dart plugins.

Install Flutter SDK by downloading it from the official Flutter site. After downloading, install the SDK and click “Add to path file” to ensure everything is set.

Creating a Simple Flutter App

In this section, you will build a simple Flutter app to understand how things work. It’s basic to give you a strong start on Flutter’s structure and key methods. You will build a simple app to say “Hello World” to a user.

To begin, open your terminal on VS Code and type:

Flutter create proj_hello_world

The project is developed on the structure:


There are different syntaxes for different applications:

  • Android – To create Android-based applications. All implementations made for Android are stored in this sub-directory.
  • Assets – A location to store all your files like pictures, etc.
  • iOS – Produces the iOS application. All implementations for the iOS app are located in this sub-directory.
  • Lib – A primary file, “main.Dart“, where one of the key codes is created.
  • Test – Used to conduct testing.

Any Flutter program will require the “main.Dart” file. Before any development, you must clear the existing code in the file; please ensure that you have done so before proceeding.

Next, you have to bring in the “Material” package to incorporate UI elements. Copy and paste the following code into your terminal.

import 'package:flutter/material.dart';

Flutter is not different from any other programming language; execution begins with the main method.

void main() => runApp(new HelloWorldApp());

Widgets are the primary focus of Flutter and are all that your code has to run. If you are wondering what widgets are, it is anything that controls the display, such as input buttons, a list, card views, tables, etc. Your entire Flutter program is an encircle of many widgets combined to provide a great user interface.

As mentioned earlier, you are going to be using widgets. For every class you create, ensure you inherit the widget class. This technique borrows from object-oriented programming (OOP). Since your application is simple and does not need to save states -a stateless widget – a building method should be present.

class HelloWorldApp extends StatelessWidget {
Widget build(BuildContext context) {
Now comes the main magic-
return new MaterialApp(
home: new Material(
child: new Center(
child:new Text("Hello world!"),

The “center” widget will run the elements while the “MaterialApp” will wrap the widget, one made up of the material.

In this case, you are adding a widget for a text field with a text; feel free to use your own. Besides the visible properties used here, “home and child,” there are many attributes to manage a complete user interface, like styling, decorations, dates, time, location, etc.  

You are almost there; it’s time to combine our code. Ensure you have the following on your code editor.

import 'package:flutter/material.dart';
void main() => runApp(new HelloWorldApp())
class HelloWorldApp extends StatelessWidget {
Widget build(BuildContext context) {
Now comes the main magic-
return new MaterialApp(
home: new Material(
child: new Center(
child:new Text("Hello world!"),

Finally, key in this command and run it.

flutter run

Congratulations, your output should be a “Hello World!” populated screen.

Flutter Testing


If you have been in the software development world, you know how difficult it gets to test that your application works fine manually. If you haven’t, you can picture building large applications with thousands of unique features. Try as you might, you cannot test the features manually. Automated tests assert that your application works correctly before publishing it to production.

Here are the automated testing categories:

#1. Unit Test

In this case, you test a single function, class, or method. Your goal is to verify that a unit is correct under various conditions. Unit tests do not write to or read from disk, receive user action, or render to screen outside the testing process. If you want to dig deeper into unit testing, run “flutter test –help” on your terminal.

#2. Widget Test

Occasionally referred to as component test in other UI frameworks. This test ensures that your widgets’ UI looks as intended and interacts as expected. You will need a test environment to test a widget as it involves multiple classes. For example, you may test a widget to confirm that it receives user actions and events. This test is more comprehensive as opposed to the Unit.

#3. Integration Test

This test covers the whole app or its larger part. In this case, you aim to ensure that all widgets and services in your digital product are working together correctly as intended in your design. This is a verification of your app’s performance. Integration tests run on real devices or OS emulators like iOS or Android. You can learn about integration tests on Flutter’s guide to integration testing.

How to Become a Flutter Developer

Today, the job market for Flutter developers is in high demand bearing in mind the advantages we mentioned earlier. If you have been considering learning Flutter, you made the right choice.

Gather some prerequisite knowledge, like object-oriented programming, preferably Java. Learning the native for Android makes hacking your way through Flutter easy.

Start with the basics, move forward to UI development, and learn how to make application program interface (API) calls. Proceed to database integrations and learn state management. Finally, wrap it with project architecture.

Learning Resources

Here are some amazing learning courses to help you break into Flutter App development. This roundup consists of Udemy courses and Amazon books.

#1. Flutter and Dart – The Complete Guide


This course is a complete guide to the Flutter SDK and its framework for building Android and native iOS applications. You will learn the basics and dive deeper into topics, eventually becoming an advanced developer.

#2. The Complete Flutter App Development Bootcamp with Dart


There is no better way to learn Flutter than taking this course on Flutter Development Bootcamp with Dart, created in collaboration with the Google Flutter team. You will know all understand all the concepts of Flutter development.

#3. Learn Flutter from Scratch


If you are a beginner looking to start with Flutter, this course on Flutter from scratch helps you understand the basics and create simple and beautiful Flutter applications. There are no prerequisites needed; you can get started quickly!

#4. Flutter Official Documentation


Whether you have a coding background or not, Flutter’s documentation will walk you through becoming an expert developer. It is also the best place to get the latest stable Flutter releases.

#5. Real-World Flutter by Tutorials (First Edition)

If you have mastered Flutter basics and want to advance, this book on Real-World Flutter by Tutorials (First Edition) is your first choice.

You will walk through from just knowing to build Flutter apps professionally.

#6. Flutter Complete Reference

This book is a detailed tackle of the Flutter framework and the Dart programming language and further dives into deep topics and best practices for Flutter application development.

The official website of this book consists of some quiz games to test your skill sets.

#7. Flutter Cookbook

This book is an adventure on how to build, debug, and scale native iOS and Android applications.

Walk through comprehensive tutorials with Flutter, and iterate through unique user interfaces (UI).

#8. Flutter for Dummies

This book, named Flutter for Dummies, is unique. It teaches you the Dart programming language.

Preview Product Rating Price
Flutter For Dummies Flutter For Dummies No ratings yet $18.39

It explains how to initialize your own frameworks and finally equips you with all essentials for riding Flutter’s revolutionary app development.

#9. Building Games with Flutter

Whether you are looking to explore or build Flutter games, this book is a comprehensive guide to building multiplatform games using Flutter’s Flame engine.

The book is procedural to ensure you grasp all steps and the best development practices.

#10. Flutter Projects

This book teaches you the Dart programming language and Flutter framework by guiding you through building real-world Apps and games.

It has practical projects that demonstrate the best techniques for Flutter App development.

Final Words

You now have a complete sense of how Flutter works and how it can help you build digital products. Flutter offers you complete dominance in application flexibility, and your imagination can only limit you.

Once you master the basics of Flutter development, you can create any application, whether web, Android, Mac, or iOS, to meet any client’s needs.  

Next, check out the best frameworks for creating serverless applications.

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