An OS X app in Swift to demonstrate using the Leap Motion Objective-C SDK.
Using the SDK with Swift requires setting up a project using the instructions on the Leap Motion Developer Portal and creating a bridging header file to expose the classes to Swift.
After setting it up you can use the Leap Motion SDK classes as you'd use any other class in Swift. This project uses a LeapMotionManager class as a singleton to handle tracking hand motions et cetera.
Here's a current screenshot just to show it working:
Both the left hand image and the right hand image are from Openclipart.org. The ball image is also from Openclipart.org.