Fantastic!
I would not trust it if I’m doing carpentry or other work where it has to be a millimeter precision, but for times when I do not have my measuring tape and need to know how wide curtains I need or the width of my window for new blinds or even the size of a picture, this app is amazing. I just tap when the circle is at the point where I need to measure, move the phone until I reach the next point, and then I have the measurements. It is brilliant!