That's funny....I had GW installed (I thought doing the work-around to get it from the Play Store). It worked fine, but when I saw this, it wasn't in the list of My Apps on my phone, so I couldn't update it. Couldn't even see it when I searched the Play Store. When I used your link though, it came up (of course), saying it was installed on my Nexus. So I clicked install, selected my Nexus as the device (even though it said it was already installed), and it downloaded to my phone and installed. Don't know why I couldn't see it in my list of apps though. Oh well, all is good now!
Now if there were only more retailers that accepted it. Like maybe EVERY gas station.