I just finished listening to the most recent episode of The Prompt and was surprised by a couple of things: first, that the boys were doing a round-robin Pick of the Week segment; and second, that Stephen’s pick was the Iconfactory’s xScope. Turns out™ I was using xScope myself earlier today—it’s a great app that isn’t as niche as you might think.

xScope is aimed at software and web designers. It gives the user a set of on-screen tools for aligning, positioning, and measuring user interface elements. Not exactly the kind of utility I’m on the lookout for. In fact, I didn’t actually buy xScope itself. It was part of some software bundle a while ago, and I bought the bundle because I wanted two or three of the other apps. xScope came along for the ride and became the sleeper hit.

Photographs and measurements of equipment are an important part of the work I do. While it’s always best to take measurements directly on the equipment itself, sometimes that’s not possible, and I have to estimate dimensions from photographs. Putting the photos on screen and using xScope to take measurements is the best way to make those estimates.


The ruler with calipers is my most-used tool. I can rotate it around and stretch it to take a series of measurements in no time. I don’t have to read the marks on the ruler; the distance between the calipers (and the angle) is given right on the ruler. This allows me to get relative dimensions with no other information and absolute dimensions if I know the size of at least one item in the photo.

If this description is giving you heart palpitations, don’t worry. I’ve done real photogrammetry and I know this ain’t it. There are plenty of errors that can accumulate in this type of measurement, and I would never pretend that this is a high-precision technique. But quite often the estimates it gives are good enough.

Sometimes I get to work with aerial photos that have been orthorectified. In these cases, I know the scale, and I know that I can take reliable and precise measurements off the photos. The ruler tool works here, too, but I tend to use the crosshair tool to get the x and y coordinates as I move from point to point.

I’m not saying the Iconfactory should market xScope to engineers who need to take measurements off of photographs—that would be an extremely niche market. But well-built tools can often be used for purposes their designers never thought of, and xScope fits in that category.