A friend of mine, Christoph Wille (PM of the SharpDevelop project), has started a Windows 8 Open Source project named "Sprudelsuche" which can be translated as "fizz search". The intention behind the app is to provide a Windows 8 styled UI for the website spritpreisrechner.at, where you can find information about where to get the cheapest gas in Austria for the current day. Also the app, from a users perspective, won't be interesting for you as a non-Austrian, it might be interesting for you as a Windows 8 app developer.
To provide an overview of the App, Chris has taken some screenshots:
The start screen
Your favorite gas stations / types.
When no GPS is available you can select the city manually.
Your selection can be pinned to the Windows 8 start screen.
Pinned gas station in Windows 8 start screen.
Enable/disable hourly auto-refresh.
As you can see, "Sprudelsuche" also integrates Bing Maps, which provides a good user experience. On the other hand it provides a bad deployment experience as Bing Maps are in still in beta state currently and because of this, deployment via the Microsoft Windows 8 App Store is prohibited (Bing Maps final will be available by the end of september). You can install the Bing Maps SDK Beta using the Visual Studio Extension Manager - search for "Bing Maps SDK".
To allow you to install and run the app anyway, Chris provides the App as a download from here. It also includes the source code. The project is available under MIT license. It also includes libraries and source code from other blogs and the SDK which are licensed under their own licenses as you can see in the corresponding projects inside the solution (NotificationsExtensions and SprudelSuche.ThirdParty).
If you're interested in some technical details, then the developer quick tour is for you.