When decorating a tree you can opt to use one of the four built in backgrounds, use a photo from the photos+video hub as a background, or capture a new background photo using the camera (e.g. place your virtual Christmas tree in your own home or garden). The placement and size of the tree on any of the backgrounds can be adjusted using drag and pinch-to-zoom gestures respectively, letting you get just the right positioning, which is especially useful when using your own photos.
Once you have finished customising your virtual Christmas tree you can pin it to the Start Screen, set the completed image as your lock screen, or share your creation with friends via social media. The trial version of My Christmas Tree lets you create as many virtual trees as you like, but if you want to using the sharing or platform integration features of the app you'll need to buy the full version.
Windows Phone Store description:
Use Your imagination and decorate the Christmas tree. Share it with your friends, send it to your family, set it as your lock screen or pin it to the start screen and get yourself into the Christmas spirit!
All of the gorgeous backgrounds, trees and decorations are hand-drawn by a professional illustrator. In addition, you can choose the background from the phone's picture gallery or take a photo with the camera and place the Christmas tree in your room or in your hand! Loads of fun for both kids and adults!
My Christmas Tree can be downloaded from the Windows Phone Store. A free trial is available, with the full app costing £0.99 / €1.29 / $1.29. The full version removes ads from the app and, as noted above, unlocks additional functionality.