Previous iterations of AirDisplay have been forced to work over WiFi (which made using AirDisplay laggy and unreliable) because for a long time, Apple rejected apps that used a USB connection. Apple relaxed its policies on apps accessing USB earlier this year when it approved Duet Display, paving the way for apps like AirDisplay to incorporate the same technology for more solid connections that cut down on lag.
In our limited testing, AirDisplay 3 used over USB worked well, with little lag, and its performance was comparable to Duet Display. There's still an option to connect over WiFi if USB is not available, but using WiFi was considerably more unreliable with a lot more of a delay when attempting to perform tasks.
In addition to USB support, Air Display 3 has also gained features from Avatron's Air Stylus app, which is being retired. Air Stylus was designed to allow people to use their iPads as pressure sensitive wireless drawing tablets in conjunction with Mac or PC-based computers, and that capability has been added to Air Display 3.
We're retiring our Air Stylus iOS app and we've rolled all of its awesome features into Air Display 3. Now you can draw with your favorite pressure-sensitive stylus directly into a Mac app like Photoshop or Motion. In Air Display 3, we've added support for all of the latest styluses. And on iOS 8, you don't even need a stylus: just tilt your finger to simulate pressure changes.Air Display 3 also gains support for pinch and zoom gestures, and according to the release notes, its WiFi features have been sped up as well. Older features like multiple monitor support (for up to four iPads), a keyboard, HiDPI options, and touch gestures are also available.
Air Display 3, which is a new app and not an upgrade from AirDisplay 2, can be downloaded from the iOS App Store for $14.99. [Direct Link]
Users will also need to download a free Mac app from the Avatron website to connect their iOS devices to their Macs. For the time being, Air Display 3 is only compatible with Macs running OS X 10.8 Mountain Lion and above, but Avatron has plans to add Windows support in the future.