There is no documentation specifically for the SketchPad as all the functionality for SketchPad is identical to ImageAnimator and is covered in the documentation for ImageAnimator.
To Download a pdf version of the documentation,
click here.
The BS Image Animator video shows the default screen set and its animation together with the additional functionality built into the app such as the loading of your own screen sets, accessing the log screen and other options.
There are additional Screen Sets available to download. These include the following :-