In our last post, we installed the MVVM Light Toolkit and defined the basic framework for a simple two-page app with the MVVM pattern. With the ViewModels we created, we now have the containers for the data, but it would be even more helpful to pre-populate them with some sample data to aid in the designing of the app.
Read more at the Falafel Software Blogs: Windows 10 Development: Adding Design-Time Data with Blend