The Todolists application for Windows Phone 7 is a personal organizer type of application with source code available for free together with a series of blogs explaining in details how the application was built. The app is created by the Telerik team using RadControls for Windows Phone and the tutorials will get you started with WP7 development, will show you tips & tricks about how to use specific WP7 APIs into your application and will show you some more advanced techniques on how to squeeze the max performance of your app. The blog series covers everything from creating the wireframes to design, adding richness and device features to using SterlingDB for blazing fast app and much more.
Check out the app and download source code!