Introduction

In this tutorial, we'll be walking through the process of deploying your Flutter app to the Google Play Store. We will use Android’s signing mechanism to create a signed APK or App Bundle, which is necessary to submit your app to Google Play Store.

By the end of this tutorial, you will learn:
- How to prepare your Flutter app for release
- How to create a signed APK or App Bundle
- How to submit your app to the Google Play Store

Prerequisites:
- A basic understanding of Flutter development
- Flutter SDK installed on your local development machine
- An active Google Play Publisher Account

Step-by-Step Guide

Preparing your Flutter App for Release

Before you can submit your app to the play store, you need to prepare it for release. This involves setting the version number and building an app bundle.

First, open the pubspec.yaml file in the root of your project and locate the version information:

version: 1.0.0+1

The version before the + is the user-facing version number, and the version after the + is the internal version number. Update these as necessary.

Creating a Signed APK or App Bundle

To distribute your app through the Play Store, you'll need to create a signed APK or App Bundle. The signature is used to ensure the app's integrity from updates to downloads.

First, create a key store if you haven't already:

keytool -genkey -v -keystore ~/key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias key

This command prompts you for passwords for the key store and key, and to provide the Distinguished Name fields for your key. It then generates the key store as a file called key.jks in your home directory.

Next, create a file named <app dir>/android/key.properties that contains a reference to your keystore:

storePassword=<password from previous step>
keyPassword=<password from previous step>
keyAlias=key
storeFile=<location of the key store file, e.g., /Users/<user name>/key.jks>

Submit your App to the Google Play Store

Go to the Google Play Console, and select 'Create Application'. Fill in the name of your app and the short description, then upload your APK or AAB file. Fill out the remaining fields and configuration settings, and hit 'Submit'.

Code Examples

Here is an example of building an APK:

flutter build apk --split-per-abi --no-shrink

After running this command, you'll find your APK files in <app dir>/build/app/outputs/apk/release/. You need to submit these files to the Play Store.

Summary

In this tutorial, you've learned how to prepare your Flutter app for release, create a signed APK or App Bundle, and submit your app to the Google Play Store. The next steps would be to monitor your app's usage and error reports to ensure it's functioning as expected.

Practice Exercises

1. Try to deploy a simple "Hello, World!" Flutter app to the Play Store.
2. Create and deploy an app that uses a third-party package.
3. Deploy an app that includes both a custom icon and a custom launch screen.

Don't forget to test your app thoroughly before deploying it to the Play Store!