A free program for Android, by Splashtop.

Splashtop Wired XDisplay is a free 10-minute session that enables you to test the product and ensure it meets your requirements. To remove the session time restriction, you can choose to buy the official version.

Through the use of Splashtop Wired XDisplay, your computer may use an Android as an additional display, increasing productivity. It allows you to utilize your Android screen for multiple activities such as hosting your favorite gadgets, like IM, Facebook, Twitter, and others, rendering screen for Photoshop, and AutoCAD, as a side-by-side display of your Word, Excel and PowerPoint, reading documents in portrait mode, accessing your Windows program via direct touch, and many more sophisticated usage possibilities.