iMultiviewer is a perfect helper, if you have several screens attached to your Mac - which are not in direct view. Imagine to work on a mac and your second screen is on the other side of a wall. Or you connected a projector to your laptop with a large projection right above you. Well, you'll get a stiff neck guaranteed. Not with iMultiviewer. It shows you exactly what you do - in realtime - on your main screen.

If you often work with multiscreen systems on expos, events and shows where you have no direct view to your external screens, you definitely know for what this application is.
Is gives you a mirrored live view of every connected display.

To give you more flexibility, gestures on Apple's Magic Trackpad and on your Laptop's trackpad are fully supported - rotate, zoom and move the mirrored image as you like. Just double-click to reset the view. Think about fancy installations with rotated, vertical or upside-down mounted displays....