In the old days, the Android app was exactly like an APK file, though it didn't take long for it to get complicated with different APKs and OBB data files. And then came the Android App Bundles for Android, with many benefits but worse: It's hard to share.
That is, even if you can download an APK from APKMirror or similar sites and install it with a click, the same is not possible with a published app such as App Bundle. To configure APKMirror created its format, APKM, and its installer, APK Mirror Installer.
What is an APKM file
Google does not stop emphasizing on the benefits of publishing apps like Android App Bundle instead of APK files: small download size, optimizing various configurations without affecting code and compile time is just one of them. Google looks at App Bundles for the future of Android
The problem comes when trying to transfer apps from outside the store: it's no longer a universal APK that works easily on other phones with the same architecture, but it's about basic and additional APK of the device in question.
To date, apps with versions of the App Bundle were not available on APKMirror, although this has now changed, when its developers have introduced a tool to do so. This is a tool APKMirror installer
These APKM files are empty file containing both an APK base file just like the other files needed for the app to be installed and used. The naming of APKMirror, though we'll probably see more of it as App Bundles' popularity expands.
How to install an APKM file
Keep in mind that the APKMirror Installer is not an installed installer It won't help you to download apps either in APK or APKM format. The app is officially published on Google Play, so it would be against the rules to simplify the installation of applications from outside your store.
That is, to access APKM files you will need to browse the APKMirror website, which is nevertheless well synced with mobile phones. You can easily tell if it's an APK or APKM file because the download button is very specific Download APK Bundle instead of Download APK. You can also see the contents of the App Bundle by clicking What is inside this APK bag?.
You will need to download the APKMirror Installer, which you can find here. APKM files are associated to open with the APKMirror Installer, so when you tap Open
Taping on it will show you some details about the app, including the version you have installed. Tap Install the package getting to the most important part: choosing the "pieces" of the right application for your mobile. The installer automatically selects the ones that best fit your phone, so in most cases you only need to press Install the app.
If you didn't sign up for the app (from 2.09 euros per month), you'll need to see a video ad for up to 30 seconds, then generate an installation file and start the installation. If all goes well, you'll see a warning the application is installed.
APKMirror is a great solution to a complex problem, and as more developers start publishing their applications like App Bundles, it will become increasingly common to need their services. Remember, yes, that request it works only to install and not to download.
APKMirror Installer (Official)
Track | Android police