Preparing Your App for Release

Introduction

Preparing a Flutter app for release is a critical step that ensures your application is polished, functional, and ready for distribution on the Google Play Store and Apple App Store. A successful release requires more than just building the app—it involves careful attention to app metadata, icons, splash screens, permissions, privacy policies, and thorough testing.

This article provides a comprehensive guide to preparing your Flutter app for release, covering essential steps, best practices, platform-specific considerations, and testing procedures.

1. Update App Name, Version, and Build Number

Before releasing your app, it is crucial to update metadata such as the app name, version, and build number. This information helps users identify the app and track updates.

Step 1: Update pubspec.yaml

Open the pubspec.yaml file and locate the following fields:

name: my_flutter_app
description: A brief description of your app.
version: 1.0.0+1

name: The app’s internal package name.
description: A brief summary of what the app does.
version: The version consists of two parts: versionName and buildNumber (major.minor.patch+build).
- major.minor.patch represents the version for users.
- build is the internal build number for tracking releases.

Example:

version: 1.2.0+5

1.2.0 indicates the app version visible to users.
5 is the internal build number for the app store.

Step 2: Platform-Specific Versioning

Android: versionCode and versionName in android/app/build.gradle are derived from the pubspec.yaml version.
iOS: CFBundleShortVersionString and CFBundleVersion in ios/Runner/Info.plist correspond to the version and build number.

2. Configure App Icons

App icons are the first impression of your application on a user’s device.

Step 1: Prepare Icon Assets

Create high-resolution icons in different sizes to support various devices.
Recommended sizes: 48×48, 72×72, 96×96, 144×144, 192×192, 512×512 pixels.

Step 2: Use flutter_launcher_icons

Flutter provides the flutter_launcher_icons package to automate icon generation.

Add the package in pubspec.yaml:

dev_dependencies:
  flutter_launcher_icons: ^0.10.0

flutter_icons:
  android: true
  ios: true
  image_path: "assets/icon/app_icon.png"

Run the package:

flutter pub run flutter_launcher_icons:main

This generates icons for both Android and iOS automatically.

3. Configure Splash Screens

Splash screens improve the perceived loading time and give your app a professional feel.

Step 1: Android Splash Screen

Edit android/app/src/main/res/drawable/launch_background.xml.
Use a solid color or image as the background.
Update styles.xml to reference the splash screen.

Step 2: iOS Splash Screen

Open ios/Runner/Assets.xcassets/LaunchImage.imageset.
Add images for different device sizes.
Update Info.plist to configure launch images.

Step 3: Use flutter_native_splash

The flutter_native_splash package simplifies splash screen configuration:

dev_dependencies:
  flutter_native_splash: ^2.2.0

flutter_native_splash:
  color: "#42a5f5"
  image: assets/splash/splash_image.png
  android: true
  ios: true

Run:

flutter pub run flutter_native_splash:create

This automatically sets up splash screens for both platforms.

4. Remove Debug Print Statements

Debug prints and logs are useful during development but should be removed or disabled before release.

Step 1: Remove print Statements

Search the project for print() statements and remove unnecessary logs.
Use proper logging solutions for production, such as logger package with configurable log levels.

Step 2: Disable Debug Banner

In main.dart, ensure the debug banner is disabled:

MaterialApp(
  debugShowCheckedModeBanner: false,
)

5. Declare Permissions and Privacy Policies

Both Google Play Store and Apple App Store require apps to declare permissions and include privacy policies.

Step 1: Android Permissions

Edit android/app/src/main/AndroidManifest.xml.
Declare only the permissions necessary for your app. Example:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.CAMERA"/>

Avoid unnecessary permissions to reduce privacy concerns.

Step 2: iOS Permissions

Open ios/Runner/Info.plist.
Add usage descriptions for required permissions. Example:

<key>NSCameraUsageDescription</key>
<string>This app requires camera access to scan QR codes.</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>This app requires photo library access to upload images.</string>

Step 3: Privacy Policy

Provide a privacy policy URL in app store listings.
Ensure the policy clearly states what data is collected and how it is used.

6. Thoroughly Test Your App

Testing is a critical step to ensure the app functions correctly on real devices and different OS versions.

Step 1: Test on Android

Use both emulators and physical devices.
Check app behavior in various orientations and screen sizes.
Test permissions, notifications, and platform-specific features.

Step 2: Test on iOS

Test on simulators and real devices.
Ensure splash screens, app icons, and permissions work correctly.
Test on multiple iOS versions for compatibility.

Step 3: Test Release Build

Generate release builds:

flutter build apk --release      # Android
flutter build ios --release      # iOS

Test release builds thoroughly, as behavior can differ from debug builds.

7. Optimize App Performance

Before release, optimize performance to ensure smooth user experience.

Step 1: Minimize App Size

Remove unused assets and dependencies.
Use flutter build apk --split-per-abi to generate smaller APKs for different architectures.

Step 2: Enable Obfuscation and Minification

For Android, configure ProGuard to shrink and obfuscate code.
For iOS, enable bitcode and app thinning.

Step 3: Monitor Memory and CPU Usage

Use Flutter DevTools to profile memory, CPU, and frame rendering.
Identify and fix performance bottlenecks.

8. Prepare App Store Listings

Step 1: Google Play Store

Create a developer account.
Prepare app listing: title, description, screenshots, feature graphics.
Upload APK or AAB file.
Fill content rating, privacy policy, and pricing information.

Step 2: Apple App Store

Create an Apple Developer account.
Use App Store Connect to prepare the app listing.
Upload the app via Xcode or Transporter.
Complete metadata, screenshots, and privacy policy.

9. Continuous Integration and Deployment

For frequent releases, use CI/CD pipelines to automate build and deployment.

Use GitHub Actions, Bitrise, or Codemagic for automated builds.
Automate testing, version updates, and release packaging.
Reduce human errors and speed up release cycles.