Make your application display sample data when it runs (Windows Phone)
By default, sample data will display in objects when you run your application (F5). After you bind an object to live data, the object will display the sample data at design time on the artboard, and will display live data at run time. When testing your application, you can return to the default behavior of displaying sample data at run time.
To make your application display sample data at run time
In the Data panel, locate the data source that you want to enable at run time.
Next to the data source name, click Data source options , and then click Enable When Running Application.
A check mark appears next to Enable When Running Application.