Ruler for measuring

Michael, I recall way back in mid 1970s, when the earth was still green, a contractor installing a sidewalk. He used a device with a wheel and as it rolled along, a display showed the distance. So, whether with an additional attachment, or, less likely alone, such should be possible as is the case with the Igrill and related required accessory. The challenge with say, the Iphone, would be if the excellerometer was not sensitive enough either alone, or in combination say, with the camera for such fine detail. I think this device from the 70s probably only measured in feet and yards.