You can also find and buy games with the Xbox Games app that is built into Windows 8 and Windows RT. Open the Xbox Games app from the Start screen, sign in with the Microsoft account—it's the same thing as an Xbox ID—associated with your Gamertag, and start discovering amazing games.
Even if you don't own an Xbox 360, you can use the Xbox Games app to get blockbuster games you'll love to play and have fun socializing with your friends. You can view your game progress, earn awards and achievements, and see which Xbox friends are online and what they're playing. And if you want to let your friends know what you're up to, use the Share charm to send links to your favorite games, your profile, and achievements.
If you have an Xbox 360, you can get games for your console with the Xbox Games app and enhance your experience on the Xbox 360 with the Xbox SmartGlass app. Xbox SmartGlass turns your Windows 8 or Windows RT device into a remote control for the Xbox 360. You can use your device to interact with your Xbox 360, so you're immersed in the movies you watch and the games you play.