More and more developers are taking advantage of the nifty new ability to start a semi-closed beta on the Google Play Store via Google+. The latest is TeslaCoil Software, makers of the customization tool WidgetLocker (among other things). If you want to try out the latest and possibly greatest version of WidgetLocker, just head for this Google+ Community and join in.
Joining the beta is quite simple. Once you join the community, click the Play Store link that's displayed on the page, go through the standard warnings and whatnot, and you'll be directed to a seemingly normal Play Store entry for the app.