How to build a Flutter app for Android?
Tags: flutter, android, software, mobile
Published: 2023-05-10 10:52:31

You might have heard that Flutter is one of the most efficient ways to develop high-quality applications. It works both on Android and iOS devices using a single codebase. In this blog post, we will talk about the steps to build a Flutter app for Android.  By following these steps, you can ensure the best user experience and security. To do that, you need to know how to:

- Add a launcher icon
- Enable Material Components
- Sign the app
- Shrink your code with R8

Firstly, you need to add a launcher icon to your app. It’s important for creating a strong first impression.
Secondly, enabling material components is important for a consistent and visually appealing user interface.
Next, signing the app is important for the security of the app and app users.
Finally, you can improve your app’s performance by shrinking your code with R8.
If you are interested in the [cost of an app](https://www.addevice.io/blog/how-much-does-it-cost-to-build-a-mobile-app), click on the link and learn about this important issue. You may also be interested in [what’s new in Flutter 3](https://www.addevice.io/blog/how-much-does-it-cost-to-build-a-mobile-app).
And now we will proceed to Flutter app development for Android.

## Adding a launcher icon
The launching icon is the first thing a user sees on an Android device. Your app’s first impression depends precisely on this. Here is how to add a launcher icon to your Flutter app for Android devices.
**Step 1:** Create an icon file. It should be in PNG format and should have a resolution of at least 192x192 pixels. This can be done in any image editor.
**Step 2:** Now you are ready to add the icon file to your Flutter project’s assets folder which is normally in the root directory of your project.
**Step 3:** Specify the launcher icon in the AndroidManifest.xml file. This file is located in the android/app/src/main directory of your Flutter project. Open the file and add the following code:
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ti2xg2s6wtfgfic518ch.png)
You need to replace the My Flutter App name with the name of your icon file.
**Step 4:** Now you are ready to test it by running the app on an Android device or emulator. The launcher icon should be displayed on the home screen of the device.
These steps will create a launcher icon that is properly sized and formatted to use on Android devices. They will help you create an appealing launcher icon that stands out on a user device.

## Enable material components
To enable material components, you need to follow these steps.
**Step 1:** Add the material component to your Flutter project. You can do that by adding the following line to your pubspec.yaml file.
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/mclspd6pip438gh98oa6.png)
**Step 2:** After doing this, you can import the material library to your Dart code using the following line:
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ynm3pjmuh94jl01i2g9j.png)
**Step 3:** Customize material components to your app
You can now change the appearance and behavior of each component. Here is an example of how to change color.
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/el90bfxzb5rg5bgi2afq.png)
Alternatively, you can use MaterialApp widget which provides access to the full suite of Material Design widgets and design elements. You can also use the Theme widget to customize your app. For example, you can specify color, accent color, typography, and more.

## Sign the app
If you are new to Flutter, you might need to know how to sign up for Android devices. You need that also to publish on the Play store to give your app a digital signature. You can use two options – deployment and upload.
You need to generate a keystore file and use it to sign your app’s APK. The important thing here is to keep it safe and secure as this contains a private key. You can generate keystore file using the keytool command-line utility. After doing that, you can use the Flutter CLI and sign it.
An important recommendation is to use the automatic cloud-managed signing for the deployment key.
Here are the steps to follow:
**Step 1. Install Flutter
Step 2. Install Android Studio.
Step 3. Set up your Android devices.
Step 4. Create a new Flutter project.
Step 5. Run the app on your Android device.**
You are ready to build amazing apps with the help of Flutter on Android devices.

## Shrink your code with R8
You can use R8 to shrink your code for a small size and better performance app. R8 is a tool to optimize and shrink Java bytecode. It is included in Android Gradle Plugin. Shrinking your app with R8 has several benefits like a smaller app size, faster startup times, and improved performance. Here is how to shrink your code with R8.
The following lines need to be added to your build.gradle file
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/06m5i3sxmbz6xwluub0i.png)
You will also need to add the following dependencies to your app’s build.gradle file:
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/qaieh4fv3tgg0qczvlay.jpg)
After adding these settings and dependencies to your build.gradle file, R8 will automatically shrink your code and optimize your app. You can enjoy the benefits of a smaller, faster, and more efficient app now.

## Conclusion
If you follow the above steps, you can use Flutter to build apps in a productive way and most importantly in a short time. This is because Flutter has multiple customizable widgets and a reactive programming model. It is also easy to find programmers as Flutter has a growing community of developers.
In this blog post, we covered basics, particularly how to add a launch icon, enable material components, sign the app, and shrink your code. You need to do more research and most importantly you can find help in the [Flutter community](https://flutter.dev/community). We hope we helped you with your exciting work.