The Android App Bundle (AAB) format, introduced by Google Play in 2018, has become a requirement for all new Android apps since August 2021, replacing the older APK format. AABs enhance app performance and reduce download sizes by optimizing APKs for various device configurations and languages, potentially increasing installation rates. Transitioning from APK to AAB involves generating an AAB binary and enabling Play App Signing, which can be done locally using Android Studio or via cloud services like Appflow. Appflow simplifies the process by automatically creating AAB binaries and facilitating their deployment to Google Play. Existing apps are not mandated to switch to AAB but can voluntarily enroll in Play App Signing to benefit from its advantages. The AAB format offers improved performance, smaller app sizes, and enhanced security, making it advantageous for both developers and users.