Hey there Netduinees!
I've made quite a detailed tutorial of how to communicate between a Windows Phone 8 and a Netduino with a cheap Bluetooth module.
The app controls the RGB of an LED based on the sliders in the app. Another way is using the camera on the phone to get the average ambient color of what it's looking at and change the LED accordingly.
I'm a Windows/Windows Phone dev so electronics is not my forte' - which is why everything in the post is probably painfully easy for everyone here. But I hope it can help out even 1 person :-)