About a year ago, Google had announced a new way of life for Android app developers – the Android App Bundle.
It makes it easier for developers to make (a) smaller apps (b)faster apps (c) instantly downloadable apps. Today, Google has updated the Bundle. Alterations have been made to how the app bundle handle uncompressed native libraries that are already on a device. Those will lead to downloads that are on average 8% smaller & take up 16% less space on a device, claimed Google.
Here’s how the Android App Bundle works in detail, as explained by Google:
Step 1: You write all your code for your app in an IDE such as Android Studio or a games engine such as Unity as you normally would.
Step 2: Now, when you’re ready to test or release the app, you build it as an Android App Bundle, Android’s new app publishing format. You still sign the app so that Google Play can verify it’s from you.
Step 3: If you haven’t already, you opt in to app signing by Google Play. If you’re releasing a new app, you can do this in a 1-click process when you upload your app. When you opt in, Play designates the 1st key you used to sign your app bundle as the upload key. This is just for security identification purposes. For existing apps, you need to visit the app signing page in the Play Console & securely transfer your app signing key to Google Play.
Step 4: When you upload your app bundle to Google Play, Play processes it & generates split APKs signed with the app signing key for every possible device configuration & language that you support. Split APKs are an Android platform feature introduced in Android L. As long as each split APK is signed with the same key, the Android platform will treat them as 1 app. You can think of a split APK as ‘part’ of an APK: to run the app, the device treats all the parts as a single app.
Step 5: When a user installs the app, Play delivers the base split APK (all the code that’s common for every device), the language split APKs (for the languages the user speaks), & the device configuration split APKs. This means the device gets just what it needs without wasted space. For updates to be accepted by the device, every release’s split APKs must be signed with the same app signing key as the original app install.
Step 6: Once your app is installed on a device, Play will deliver additional split APKs on demand.
Google claims the new model “results in dramatically smaller apps that take less time to download & less space on a device.” Building an app bundle in Android Studio is much the same process as building an APK. Game developers using Unity can also build app bundles in Unity’s 2018.3 beta release & later.
