One constant in the smartphone world, at least for Android, is that applications and games come as 'APK' files - witness the huge number of sites offering APK files for sideloading, even though this isn't sensible in terms of security. However, as of next month Google is changing things, with an emphasis on a new server-driven 'app bundle' format. The benefits are quoted below, though at least partly the change will be in that future versions of Android may not run APKs and the troublesome side-loaded/hacking/malware world will be a thing of the past.

From the Google blog, addressing Android app developers:

Since we launched the Android App Bundle in May 2018, we’ve seen our developer community embrace this new standard to benefit from streamlined releases and advanced distribution features. There are now over 1 million apps using app bundles in production, including the majority of the top 1,000 apps and games on Google Play...

To bring these benefits to more users and focus on modern Android distribution that benefits all developers, Google Play will start requiring new apps to be published with the Android App Bundle starting August 2021. This will replace the APK as the standard publishing format.

If you haven’t made the switch to app bundles yet, here are some of the benefits you’re missing:

• Android App Bundle: Google Play uses the app bundle to generate and optimize APKs for distribution for different device configurations and languages. This makes your app smaller (on average, 15% smaller than a universal APK) and faster to download, which can lead to more installs and fewer uninstalls.
• Play App Signing: Play App Signing, which is required for app bundles, protects your app signing key from loss by using Google’s secure infrastructure and offers the option of upgrading to a new, cryptographically stronger app signing key.
• Play Feature Delivery: Used by more than 10% of the top apps using app bundles, Play Feature Delivery gives you the ability to customize what feature modules are delivered to which device and when, with install-time, conditional, and on-demand delivery modes.
• Play Asset Delivery: Reduces user waiting time by dynamically delivering large assets while cutting delivery costs. Games using Play Asset Delivery can use texture compression format targeting, so your users only get the assets suitable for their device, with no wasted space or bandwidth.
• Future improvements: Soon, Play App Signing will start rolling out APK Signature Scheme v4 to select apps making it possible for them to optionally access upcoming performance features available on newer devices. Tune into the Google for Games Developer Summit on July 12 to find out more.

Just to be clear, the app bundle requirement applies to new applications only. Existing apps are currently exempt, though I suspect that Android 13 or 14 will enforce the use of app bundles for all end user applications.

It all seems like a good idea, mind you. For games especially, you can be off and running far sooner, with large higher level downloads waiting until you actually get that far in the game, by which time you're hooked and are prepared to wait.

For you and I, general app end users, little will appear to change, of course. Which is good, and Google have a good track record of not breaking things as they evolved their Store and app formats over the last decade.