Luna Display - Hardware that turns the iPad into a wireless second display
Fliqlo Screensaver - A screensaver that displays the time using a flip clock.
Duet Display - With Duet Display, you can transform your iPhone or iPad into a second display to expand the screen space of your PC or Mac system.
Padbury Clock Screensaver - Minimal screensaver for Mac
Mountie - Mount a second screen (iPad/iPhone/tablet) to your MacBook
Really Slick Screensavers - Really Slick contains free 3D OpenGL screensavers.