Take a picture of a scene and later reconstruct the distances by tapping points on the picture. You need to have a special pattern (we supply the PDF) which you print out and place in the picture. This version can measure distances along the ground, and the vertical distances of objects from a point on the ground to a point in the air. Accuracy depends on several factors, including how far away the object is, lighting, steadiness of camera etc. For objects near the pattern, accuracy can be fractions of an inch.