The Xbox One doesn't land in the hands of customers until Friday, 22 November, so in the meantime they'll just have to sit around with the app in envy.
Nonetheless, the SmartGlass app will be useful for the Xbox One when made available. iOS 6.0+, Android 4.0+, and Windows Phone users will be able to have a second-screen experience for their console.
Specifically, SmartGlass allows you to navigate your Xbox One console using your device’s keyboard and touch, control your media and set-top box with the SmartGlass remote control, browse the web on your TV using your mobile device, enhance what you are watching or playing with SmartGlass companions, and increase performance with faster connections and reliability.
The app was first made available for the Xbox 360 in 2012, and is now extending to Microsoft's highly anticipated new console.