The reason for this, that the current version does not work anymore, has nothing to do with changes to the Play Store. This extension use manifest version 1, but it was announced deprecated in Chrome 18 and support stopped with Chrome 20. As of Google Chrome 20+ all extensions require to use the manifest version 2. Thus, the extension stopped working.
I created a modified version of the extension to work with Chrome 20+. You can find it here: http://forum.xda-developers.com/showthread.php?t=1809458