I created this card type tool. Im a studying Engineer in High School, and ive been working on this in my free time. I hope to have a few prototypes made and have it perfected before school starts back up again in September, so that I can show it to my teacher.
It has a ruler in millimeters on the left side, and a ruler in inches on the right. It has a radius ruler type thing down the middle. It also has a bottle opener.