Featured in: CNN, The New York Times, Chicago Tribune, The Guardian, and many more. #1 Laser Ruler app in United States #1 Laser Ruler app in Japan #1 Laser Ruler app in United Kingdom #1 Laser Ruler app in Australia Lazer Ruler uses the camera lens height and the iPhone camera angles as parameters to calculate the width, distance and height of the object. Lazer Ruler calculates the camera angles automatically. You have to set the iPhone camera lens height from the ground. PLEASE BE NOTICED: You must read and understand the instructions carefully to use this app and measure distance, height, width. You must set the iPhone camera lens height(above your foot) in the app first. The Camera Lens Height can be set in the “LensHeight” of this app. Usually this set to about 1.5 m. There are thousands of customers using this app very well every day!