Two spine surgeons performed the measurements with Scoliometer and Scoliogauge.  The overall intraobserver variability was 0.954 and the overall interobserver variability was 0.943 for the scoliometer set, whereas the intraobserver variability was 0.965 and interobserver variability was 0.964 for the scoliogauge set.  Smartphone-aided measurement for ATR showed excellent reliability, and the reliability of measurement with either scoliometer or scoliogauge could be influenced by Cobb angle that reliability was better for curves with larger Cobb angles.
Scoliometer
Scoliogauge, has been developed for the measurement of ATR on iPhone smartphones.  Two spine surgeons performed the measurements with Scoliometer and Scoliogauge.  The Scoliogauge measurements were conducted on an iPhone 4 smartphone.  The overall intraobserver variability was 0.954 and the overall interobserver variability was 0.943 for the scoliometer set, whereas the intraobserver variability was 0.965 and interobserver variability was 0.964 for the scoliogauge set.  Smartphone-aided measurement for ATR showed excellent reliability, and the reliability of measurement with either scoliometer or scoliogauge could be influenced by Cobb angle that reliability was better for curves with larger Cobb angles.
Scoliogauge
The Scoliogauge measurements were conducted on an iPhone 4 smartphone. 
iPhone 4 smartphone