I looked on that website out of curiosity but could see no reference to your View Catcher.
I guess it is basically a little plastic framing device to help you visualize the shot without putting the camera to your eye. Tried something similar decades ago by carrying an empty slide frame but have found over the years I can look at a scene and pretty well imagine how things could be framed without the aid, the other downside is that it cannot allow for different focal lengths.
Still, if you find it helpful then that is great and thanks for sharing.
