From UnCrate & Material Six:

Forget the stickers — if you’re looking to add a bit of wooden warmth to the back of your iPhone, these Material 6 Wood iPhone Backs ($90-$100) are the only way to go. Available in a variety of impressive finishes, they come complete with a tiny screwdriver that lets you go from breakable glass to sturdy wood in less than a minute. Oh, and they’re just as easy to replace with your original glass back should a Genius Bar appointment be necessary.