The BEST Ruler - 3D Measure ever in app Store, turns your iPhone into a tape that measure the width, distance and height of a object any where in any time!
3D Measure uses the camera lens height and the iPhone camera angles as parameters to calculate the width, distance and height of the object.
The 3D measure will calculate the camera angles automatically.
You have to set the iPhone camera lens height from the ground.
The Camera Lens Height can be set in the “LensHeight” of this app.