Air Display (Android) app for $4.99

Ever wish you had an extra display for your Mac or Windows computer? There's an app for that. With Air Display, you can use your Android screen as a wireless display, to extend your computer desktop. In order for Air Display to work, your computer and Android device must be connected to the same Wi-Fi network. Air Display's performance is extremely responsive, employing a unique dynamic compression algorithm. On a typical Wi-Fi network, mouse cursor refreshes are indistinguishable from a wired mouse. Air Display works in both landscape and portrait configurations. Just rotate your screen, and it automatically reconfigures. Air Display makes a laptop much more useful by increasing its usable screen size.+