Duet Display is a brand new application that lets users repurpose old and new iOS devices including the iPhone, iPad and iPod touch, and turn them into handy second displays for OS X laptops and desktops — and it’s available for download right now.
Once both applications are installed, users only have to connect their iOS and OS X devices using either a 30-pin or Lightning cable, and they’ll be able to extend the OS X desktop to the second chosen display.
The app is supposed to work with Macs running any iOS version from OS X 10.9 to the latest official Yosemite build, and devices running at least iOS 6.0.
Unfortunately, for the time being, older iPads or iPhones stuck on iOS 5.1.1 aren’t supported, even though the developer says in the app’s description that the iOS 5.1.1 devices should also be compatible with Duet Display.
Furthermore, the app only supports one iPhone and/or iPad at a time, which means users can’t turn more than one iOS device into a display for their Macs.
Finally, a Duet Display version for Windows is also in the works apparently, and should be launched at a later date in the future.