This app is a useful utility for any orthopaedic surgeon or physician who treats limb-length discrepencies or needs a limb-length, trunk-height, or total height prediction tool. Based on the publications and equations developed by Dr. Paley, and produced by Dr. Paley himself, the app is organized into 6 sections: discrepancy, bone length, fetal, height, sitting height, achondroplasia, and “other charts” which includes supporting tables, charts, and diagrams. Each main section is organized into sub-categories to help a provider identify the appropriate equation. Once the proper function as been selected, the app is as easy as entering the patients age, gender, and relevant values (limb length, current height, discrepancy, etc.). Overall, the app provides a free and invaluable tool for physicians who use the multiplier method in their clinical practice.