That day has finally arrived, and Air Display is now Retina ready, with support for OS X’s built-in HiDPI mode.
HiDPI is a hidden feature in OS X that renders with a double resolution. You may or may not know about HiDPI, which has been concealed by default because there are few ultra high resolution displays that are able to take advantage of the setting.
As an Air Display user, I can say first hand that the new HiDPI mode looks fantastic on the iPad’s Retina display. Air Display is compatible with most Macs running OS X Snow Leopard or later.