In May at GoogleIO, Google announced that it would begin supporting multiple .APK files, and finally this feature has come to fruition. To get started using this new feature, visit the Android Developer Console and click on your application. At the top of the application information you will notice that the upload .apk feature is now gone. It has been moved to a new tab at the top of the window, "APK files".
Using the Multiple APK Tool
Each of the .apk files that you upload to the Android Developer Console are examined. The system looks at the MinSDK version and the Target SDK version. The new features allow publishers to maintain multiple .apk files that target different screen versions, different version numbers, and OpenGL support. This is simultaneously a boon, and a potential disaster. It should decrease the difficulty of maintaining code that targets and supports different feature sets, but at the same time it supports the further fragmentation and differentiation of different Android devices. In an ideal world, the platform would be standardized in such a way that multiple versions wouldn't be necessary. In the practical world, Google continues to update and improve the API and platform. They break backward compatibility, and come up with new and better ways of performing software development and achieve better user interactions. This means that multiple .apk files will end up supporting the practical fragmentation of the platform.
One of the best ways to leverage these new abilities will be to fork applications at major points in platform revisioning. For example, it will soon make sense to have 3 different APKs, depending on how much historic support is desired. The first group would be platform versions 1.5 - 2.1. The second group would be 2.2-3.2. The final group would be the new Ice Cream Sandwich 4.0 platform version.