The InstruMMents pen uses the right kind of technology to upgrade an age old user experience. The pen replaces the trusty-old yet potentially-frustrating measuring tape, presenting itself as a vastly smaller, and infinitely more powerful alternative. Using a magnetic roller and a guiding light, the dimensioning pen can measure everything from straight lines, to curves and even corners. It doesn’t have an end, like a tape, so you can go on and on for meters (feet, if you don’t like the metric system!). The pen is accurate to the nearest 0.1mm, and syncs with your phone to display and even record measurements. The pen comes with a sensor that allows you to capture contours of the things you measure, so it doesn’t act as just a scale, it acts as a contour gauge too… More at YD.
Somehow I have missed this product in the past, but it looks amazing.