Proportional scale
I was reading the article on math today and they were talking about the usefulness of a proportional scale to increase or decrease pattern sizes. There is an app on iTunes called proportional scale for $1.99. It is easy to use. I had decided to order one and was looking at the different places I could order it when I saw the the information for the app at the bottom of the google search page. I am just putting the information out. I am not affiliated in any way.