Virtual Slide Rule app analytics for December 31

Virtual Slide Rule is a fully functional mathematical tool. Heavily used before the invention of the pocket calculator. These are hard to find these days, but we have a small collection (including a few unopened pocket rules and one eight-foot educational version that used to hang on the wall in the front of a high school chemistry or physics class). Virtual Slide Rule comes complete with instructions. Just the thing to geek-out your iPad.