Measure is an app developed by Google specifically for Tango-enabled phones that allow people to measure object just by pointing the camera. Read more about Measure  

There are lots of apps in the Google Play store that claim to be able to measure the distance between two points just by pointing the camera, but that’s not possible. At least it wasn’t possible until the new Tango-enabled phones have arrived.
Thanks to the set of two cameras that are used on these devices, getting a proper augmented reality experience is now feasible, and one of the byproducts is that users can also measure various distances and angles that are in the frame.
People can measure length, width, height, and even the volume of objects. Furthermore, it’s possible to create blueprints of the measurements and to take a picture so that you can share with your contacts.
It’s important to know that all the measurements are estimated, and the app works best indoors.