Measure App in iOS 12
As part of the new iOS 12 AR features there is a Measure app that allows you to measure things in 2D or 3D.
The Measure app is installed as part of iOS 12 and it allows you to quickly measure a straight line. In the demo we saw Apple measure several lines of a 3D object to quickly get the measurements. This is something that is handy if you don't have a tape measure.
Apple's Measure app also automatically detects a rectangle or square and can show you the dimensions of it on your phone without any other apps or objects for scale.