Windows Phone 8 is getting popularity. Fast. Soon it'll have really lot of applications. If you are new to Windows Phone 8 App development, this is the great place to start learning. This app can get you started.
Concepts covered. Button Checkbox Hyperlink ListBox MediaElement Control PasswordBox Progress Bar Pivot Control Radio Button Scroll Viewer Control Slider Control Textblock Control Textbox control Web browser Page navigation Passing parameters Application Bar Keyboard Touch input Files & Folder Text file Reading Text File Setting UI