As stated on their website "Leap represents an entirely new way to interact with your computers. It’s more accurate than a mouse, as reliable as a keyboard and more sensitive than a touchscreen. For the first time, you can control a computer in three dimensions with your natural hand and finger movements." So you're still asking what is it? Well think of it as kind of an Xbox Kinetic for your computer. It tracks your hand movements and allows you to control your computer. The video above best demonstrates this.
This could open up a lot of creative capabilities for developers. The 1st thing that comes to mind is 3D modeling. Imagine if you could use your hands to sculpt a 3D model, much like a sculptor using his hands to manipulate a block of clay. The cool thing is that its only $75.98! You can also sign up as a developer to develop your app to utilize this new technology. I'm sure we will be hearing more from Leap Motion in the future. You can order your Leap Motion Here