Comparison

Bone Ninja vs Paley Growth Multipliers

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Bone Ninja

This educational tool helps orthopedic surgeons learn to analyze and correct long bone deformities using digital radiographs. It provides tools for measurement, drawing, and simulating osteotomy solutions, based on established surgical methodology.

Highlights
  • Radiograph analysis of bone deformities
  • Digital measurement and drawing tools
  • Osteotomy simulation with cut-out tool
  • Upload and analyze personal radiographs
  • Comparison with suggested correction solutions
  • Educational tool based on established methodology
Features
Read full description

Bone Ninja is a teaching tool developed by two orthopedic surgeons who specialize in limb deformity correction: Dr. Shawn Standard and Dr. John Herzenberg. It is designed to help surgeons learn to analyze long bone deformities. Bone Ninja comes pre-loaded with radiographs of normal legs and deformed legs. You can analyze the provided cases or upload your own. Once your analysis is complete, you can then use the cut-out tool to try different osteotomy solutions. Suggested solutions for the provided cases are available for comparison. Bone Ninja includes tools for drawing lines, measuring angles, measuring lengths, and calibrating the magnification. The cutting tool allows you to manipulate one or more fragments to simulate correction of single or multilevel deformities. The analysis of the radiographs is based on methodology taught at our annual Baltimore Limb Deformity Course (BLDC), now in its 22nd year (DeformityCourse.com). We developed this app to supplement the BLDC and look forward to feedback from attendees and other users. Bone Ninja is not presented as a clinical tool, but rather an educational tool. It will not “automatically” analyze deformities. The student must first learn the methodology of analyzing and planning deformity correction in order to use Bone Ninja. Bone Ninja is a 21st century mobile alternative to pencil, ruler, goniometer, and paper. Bone Ninja will be periodically updated by adding more case examples, more explanations, and more tools. The name “Bone Ninja” is intentionally whimsical and reflects our philosophy of teaching as “infotainment.” Enjoy! Disclaimer The Bone Ninja App is designed for educational purposes only. The intent is to train physicians how to analyze long bone deformities. The Bone Ninja App is not intended to be used for medical diagnosis or treatment. In view of the possibility of human error or changes in medical science, neither the authors nor the developer warrant that the information contained in this software is accurate or complete and they are not responsible for any errors or omissions or the results obtained from the use of such information.

About

Paley Growth Multipliers

Features
Read full description

Paley Growth Multipliers- Orthopedic Multiplier & Limb Length Calculator The Paley Growth Multipliers app is a professional multiplier app designed for orthopedic and pediatric use, providing accurate height prediction, bone growth analysis, and limb length discrepancy (LLD) calculations using the proven Paley Multiplier method. This Orthopedic Multiplier App allows clinicians to input patient age, sex, and limb measurements to calculate growth remaining, mature height prediction, and future limb length outcomes to assist in treatment planning. Key Features • Height Prediction and mature height prediction based on the Paley multiplier method • Growth Multiplier for predicting skeletal growth and bone growth • Limb Length Calculator for femur and tibia lengths • Bone Length Predictor to predict bone length at maturity • Pediatric LLD Calculator for Limb Length Discrepancy (LLD) • Limb Discrepancy Prediction for both Congenital LLD and Developmental LLD • Epiphysiodesis Timing Calculator to assist with surgical planning • Growth Remaining and pediatric bone maturity assessment • Integrated CDC Growth Charts support (CDC growth charts app) • Achondroplasia height and growth analysis • Scanogram calculations • Foot length discrepancy and overall bone length evaluation • Pediatric orthopedics calculator and congenital discrepancy calculator • Planning support for procedures such as inclined osteotomy Built for pediatric orthopedic surgeons, specialists, and clinicians, the Paley Multiplier app supports clinical decision-making by combining reliable multiplier data with intuitive tools for height prediction, limb growth analysis, and discrepancy management. For educational and clinical support use only. Medical decisions should be made by qualified healthcare professionals.

Screenshots

Paley Growth Multipliers4 screens

Verdict

The call

The clearest difference is price: Paley Growth Multipliers at Free against Bone Ninja's $49.99. Paley Growth Multipliers also leads on device support (3 vs 1). Bone Ninja's advantage is iOS requirement (8.0 vs 13.0). On update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Paley Growth Multipliers is free to download; Bone Ninja costs $49.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Bone Ninja ships an update every 4 months, Paley Growth Multipliers every 2 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

Scorecard3 real differences · 7 level
Bone Ninja versus Paley Growth Multipliers: the parameters behind the verdict, then further details
ParameterBone NinjaPaley Growth Multipliers
Price$49.99Free — better
Rating3.8 (4 ratings) — better—
Positive reviews90.0% of reviews—
Number of ratings4 — better—
Update frequencyEvery 4 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPadiPhone, iPad, iPod — better
Requires iOS8.0 — better13.0
Further details — not scored
Size34 MB72 MB
Age rating4+9+
DeveloperLifeBridge HealthTenet Florida Physician Services II, LLC

In-app purchases

None

Bone Ninja

No in-app purchases

None

Paley Growth Multipliers

No in-app purchases

Questions

Is Bone Ninja free?
Bone Ninja costs $49.99, with no in-app purchases.
Is Paley Growth Multipliers free?
Paley Growth Multipliers is free to download, with no in-app purchases.
Do Bone Ninja or Paley Growth Multipliers have ads?
Neither Bone Ninja nor Paley Growth Multipliers shows ads.
Which is updated more often, Bone Ninja or Paley Growth Multipliers?
Bone Ninja ships an update every 4 months, and Paley Growth Multipliers every 2 months. Most recently, Bone Ninja was updated on November 1, 2026 and Paley Growth Multipliers on November 3, 2026.

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