How to Download APK Files (Android Apps) from Google Play@ 2013/03/15
This does not mean that you can wade into the store and start downloading all of the premium apps and games you’ve always had your eye on. This is not a tool for piracy, but it will enable you to download the APK for any free apps.
Note: Using APK Downloader is against Google’s Terms of Service as it involves accessing Google Play using means ‘other than through the interface that is provided by Google’.
You can download a copy of the extension by paying a visit to Code Kiem. You will need to right click the link to the latest version of the extension and select Save Target As.