Range of motion by measuring angles is frequent need in every day clinical tasks during patient examinations by orthopaedic surgeons, physicians, physical therapists and veterinarians. Commonly used method is to measure manually with a classical goniometer the range of motion of a patients joint. Often these manual measurements are inaccurate and depend on the individual interpretation. 
Augmented reality (AR) offers a novel method of blending virtual and real word. The measured angles with the advent of the augmented reality technology delivers accuracy and repeatability. Expensive motion capture data system offers Augmented Reality (AR) but this are a privileges of special costly scientific labs. 
Apple developed and popularised (AR) Augmented Reality technology readily available for its devices, thus  miniaturising expensive high tech labs inside your iPhone in front of you screen.
    The AR orthopaedic GoniometerApp is medical software aimed for orthopaedic surgeons, physicians, physical therapists and veterinarians providing tool that allow doctors to:
- determine the most accurate possibly way, in live images directly from your the camera in space angles thus estimating easily range of motion. By marking three points  by touching  over with the phone’s screen a colourful  sphere is printed  in augmented reality each time  while seeing the joint of the patient in screen. 
Angle values are printed  sequentially after measurement on the screen, while you can continue measuring and choosing another set of three new points of interest, by easily ‘grabbing’ the last two points of measurement , without loosing their last positions. By ordering the patient to place his extremity in new  position you can register, while seeing the last measurement in space in Augmented Reality. 
Point tip sphere is the ’ target cross’  from which the spheres appears during registration each time the screen is touched. The positional calibration of pointer tip sphere in AR can be easily done by allowing the user to adjust the XYZ position of the pointer tip sphere by pressing the directions buttons accordingly. This feature enhanced the accuracy of sphere placement during measurement over joints in Augmented Reality (AR).
 In case the user needs to measure more accurate the range of motion the following method is offered. First the Case i-Phone -Probe tool (CiPT) - a device dedicated for surface registration- should be 3D printed after downloading the appropriate 3D files according to user’s iPhone model from developers site. The device consist of the case, in which the iPhone sits and the rod. Rod has a predefined length (25 cm) and it is attached perpendicular to the phones case. The other side of the rod is the side that acts as mechanical pointer tip location. The pointer tip sphere in augmented reality (AR) by the app should coincide with the mechanical pointer tip location of the rod in order to measure accurate. For achieving maximum accuracy possible-which is influenced by user’s dimension’s i-Phone device the following a calibration manoeuvre should be done - by simply pressing the directions buttons over the screen the x y z position of  pointer tip sphere in augmented reality are adjusted accordingly, aiming the pointer tip sphere in AR to be aligned in all dimensions and coincide over the mechanical pointer tip location of the rod of the  i-phone in Case.
By default the distance of Point tip sphere is 25 cm away from camera (z ) By pressing  the + or - button the distance is adjusted respectively
In the intermediate row the + - button adjust  the (x) distance of Point tip sphere to camera in space. 
In  the last row by pressing the +or - button the (y) value from the Point tip sphere in space  to the camera is adjusted likewise.
The spheres can be changed in size  (r) - adjusted by pressing - or + button accordingly - or colour for better handling of the points and helping physician to deferentiate  between two different measurements (flexion and extension or external rotation versus internal).
Save the measured values and results as a screenshot to the photo roll for later review or consultation.
    Augmented reality offers precision and accuracy because points are taken in 3D space. During the test patients are not constrained by any device and have a total freedom of movement. The ability to integrate -regardless of the camera position -  live imagery and measure the angles and estimating the range of motion concurrently makes the app a simple and useful tool in clinical setting.
    In a busy everyday practice, measuring angles by the classic way namely  classic orthopaedic goniometers , is time consuming and cumbersome. Orthopaedic goniometers must be not be physical present any more. The app offers a very convenient and  accurate way to perform measurements of angles in space . The app is not a simple goniometer, is an enhanced product which helps to monitor objectively the course of the treatment and evaluate optimally  joint motions. This App is particularly useful especially in clinical settings where you need a quick results without losing time.
    All information received from the software output must be clinically reviewed regarding its plausibility before patient treatment! The ARorthopaedic Goniometer App indicated for assisting healthcare professionals. Clinical judgment and experience are required to properly use the software. The software is not for primary image interpretation.