Puppet2D is a tool for Unity3D that allows you to quickly set-up your 2D character for animating. With this tool you can create 2D skeletons, skin your characters to the bones, and create really easy to use controls that make animating the characters a breeze.
To bring up the Puppet2D window, select the Puppet2D menu and go to Window>Puppet2DWindow. All the creation tools are contained in this window.
To begin creating your puppet you'll want to get your character ready to be “rigged”. In Unity go into the scene view and click the 2D button at the top of the view. Drag in your 2D character sprites and put them into a locked layer. This is useful so you don't end up accidentally clicking on it when your trying to draw bones or controls. Now your ready to start creating the bones.