1. What are Google Play Store expansion files?
Google Play currently requires that your APK file be no more than 50MB. For most applications, this is plenty of space for all the application's code and assets. However, some apps need more space for high-fidelity graphics, media files, or other large assets. To make this process easier for you and more pleasant for users, Google Play allows you to attach a large (2GB) expansion file that supplement your APK.
Google Play hosts the expansion files for your application and serves them to the device at no cost to you. On most devices, Google Play downloads the expansion file at the same time it downloads the APK, so your application has everything it needs when the user opens it for the first time.
2. How to know if I need expansion files for my Android app?
In case you're not sure if your app has more than 50MB, feel free to request a test build (Instant build) for your app and check the binary (.apk) size.
3. How to enable Google Play Store expansion files for brick&mobile App Builder apps?
Please follow these steps Your App Dashboard -> Application Settings -> Platform Specific Options -> Android Application Licensing Public Key and paste your Application Licensing Public Key.