Fellow MVP and owner of In the Hand, Peter Foot has published a number of helper classes for developers targeting both Windows and Windows Phone. I particularly love that these enable developers to “build charming apps!”
Charming ApplicationModel
Charming Display
Charming NFC Share
Charming Popups
Charming Search
Charming Settings
Charming Share
Charming Storage
Get them directly from NuGet or visit the CodePlex site for more information.