Air Display is an excellent system utility that lets you use iOS devices as second monitors. The solution is made up of two different applications. The first one, the one I am reviewing here, is called Air Play Connect. This free app is available for Windows as well. The second application can be installed on Android and iOS, but it is not free. Currently, it sells for $9.99 on the App Store.
The installation is quite easy. All you need to do is follow the instructions that the installation wizard gives you and then restart your Mac when the process is finished. After that, you will be able to access Air Display settings from the System Preferences application. There are quite a few different features that you can enable that improve the experience. The first one is touch control input, which allows you to use touch gestures on your iPad to control the applications on your Mac that are located on your second screen. Then, if you have Retina displays like the iPad 3 or 4, you can take advantage of those great resolutions and experience better image quality.
In my testing, setting up the Air Display Connect app and the iOS app was a smooth experience. I was able to get everything working in less than a minute. With the applications synced and activated, I was able to drag windows to my new wireless second screen and all the windows looked great. Controlling the second screen with touch gestures was great. The only problem I detected with this app are videos. They play really slowly on the second screen. This is understandable, though, since the app is probably using VPN technology or something similar to stream data back and forth, and video requires a lot of bandwidth.
In short, Air Display allows you to use your iPad screen as a second monitor and even use it as a touch-enabled input device. It works like a charm and it couldn't really be any easier to set up.