Read original post by Igor Ralic at Igrali
To share statuses on Facebook from your Windows Phone app, all you have to do is use a launcher called ShareStatusTask, and the system takes care of the rest (in case your phone is connected to social networks where you’d like to share). In cases other than simple statuses or links (for example, photos), you need to take care of connecting your app to Facebook yourself. This would be a tricky thing if you had to write all the code yourself, but luckily there’s a library called Facebook C# SDK that handles much of the trouble for you. Still, you need to write some code and authorize your app to access someone’s Facebook, and this article is all about that.