Google has released an app called ‘Measure App’ for all the devices that support ARCore technology. Users can download the app for free on the Google Play Store, provided they have already installed the ARCore app, which makes the new Measure App work.
As the name suggests, Measure App measures things. It uses the camera on your phone, which is compatible with ARCore of course, to measure the length and height of objects. Here's a video by Google AR and VR on youtube explaining how the app works.
You have to move your phone around the space to find flat surfaces such as tabletops or the floor. Textured surfaces are preferable. Next, you must drag the length tool or the height tool into the scene and adjust it to the size that you want to measure. Now, tap the camera icon to take a photograph that you can save, or tap the trash icon to start from scratch.
It seems like a good tool get a rough estimate of lengths and heights in a pinch. We don't always carry a measurement tape with us, and so the next time you want to purchase furniture for your room, and want a quick estimate of the dimensions of the floor, just use the app!