As we're all aware, no tiny computer-like device is official until you can play Solitaire on it. So by unwritten law, the Apple Watch is now 100% official.
Solitaire from MobilityWare now offers Apple Watch support, along with Daily Challenges. You can also keep track of your own challenge progress, and see when the next set is due to become available, from the watch. Now all we need is Minesweeper and the transformation will be complete.
You can grab Solitaire off the App Store now for free.