DisplayPad is an incredible iPad app that lets you use your iPad as a secondary monitor over wifi with use of the touchscreen interface. DisplayPad is available in the app store for $2.99 there are competitors such as the more popular Air Display for $9.99 and iDisplay for $4.99. At $2.99 DisplayPad is a steal!

Upon opening the app for the first time you are prompted with instructions on how to install the software onto your computer, like below:

The install takes a few minutes and requires an a computer restart. DisplayPad adds an icon on your menu bar and now you are ready to use your wireless second display!

To get this app up and running you must go to the icon on your menu bar and select your iPad (which will only show if the app is open). You must do this every single time you exit the app or switch applications. DisplayPad truly makes your iPad into a second monitor. You have the same options as if you actually connected a second monitor to your computer, except better. You can use the touch screen to navigate through the screen on the iPad, tap to click, two finger tap to right click, and scroll with two fingers (although, I find myself naturally going back and running my fingers across my laptop screen and to my surprise the mouse remains stationary). You can also take advantage of the screen rotation and flip your iPad anyway to use it as a second monitor. Every time you flip your iPad your computer resets its display settings to account for the arrangement change of the iPad to the screen.

The iPad surprisingly has very minimal lag. You can stream movies on it and watch them uninterrupted. I have tested the display with many Mac OS X features and it seemed to work seamlessly with all of them except spaces. Below is a screenshot of the iPad in exposé

DisplayPad can be used in any arrangement with your screen or can be mirrored, like the picture below. When you mirror the screen the resolution of your computer automatically matches that of the iPad.

DisplayPad is a great app and can be used as if you would use a second display except with more features. The only negatives that I found was that it did not work with spaces and the fact that you must sync your computer with the app every single time you close out of the app, but if those are the only negatives that's not bad. I definitely recommend buying the DisplayPad iPad app and at $2.99 I would get this one over the competitors.