While the Nokia Lumia 920 has optical stabilization to minimize the impact of camera movements, other Windows Phones lack such features. SteadyCam is a Windows Phone 8 app that hopes to help make up for things by only taking a photo when there is no movement detected from your Windows Phone.
The interface is really no-nonsense in that all you have is the viewfinder. You take your photo as you would otherwise by using the hardware camera button (sorry, no screen touch shutter support). If the app senses any movement in your Windows Phone a message window will pop up telling you hold things still.