The short version:

Click on a hand or foot followed by a target, and run the utility to magically have it stay attached to the target.

The long version:

Similar to inverse kinematics, LimbStick is a utility that uses a mathematical process of calculating the joint parameters needed to place an appendage (hand or foot), in a given position and orientation relative to the node selected to follow.

The calculations are made across a partial or full animation to ensure that the selected appendage perfectly follows the selected target node.

Check out the quick teaser video below. For a more in-depth walk through the utility, check out the usage examples videos below that.