Gowalla is an extremely popular location-based social networking game. It is one of the most used apps on the iPhone. Its often compared to foursquare because it allows you to share your locations, experiences, and pick up stamps for their 'passport'.
There some apps that come to Android from the iPhone and are not as good as their counterpart but the developers are working hard to make this app just as good if not better. They posted this on their blog, "Our goal has been to do this right and provide a premium experience on the Android platform. We don't want it to play second fiddle to the iPhone." You could previously use Gowalla on Android through their mobile site but the native app is a welcome addition. Check out the video demo and if you get in on the action, scan the qr code and install it.