iOS developers have come up with some amazing augmented reality apps in the past. Apple is getting a whole lot more serious about this technology though. ARKit allows developers to create amazing experiences for iPhone and iPad.
Visual Inertial Odometry (VIO) to accurately track the world around it. VIO fuses camera sensor data with CoreMotion data. These two inputs allow the device to sense how it moves within a room with a high degree of accuracy, and without any additional calibration.
Your iPhone or iPad can analyze the scene in the camera view and find horizontal places in any room. ARKit detects tables and floors and lets you place objects. You will need to be an Apple Developer to play with it. More info is available here.