# AO Surgery Reference vs Multiplier

The clearest difference is monetization model: AO Surgery Reference at free against Multiplier's paid. On price, rating, review sentiment and ratings volume there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Multiplier holds the better App Store score, 4.6 against 4.4. Both are backed by a comparable volume of ratings — 14 and 24 respectively. Written reviews complicate that: 86% of AO Surgery Reference's written reviews are positive against 83% of Multiplier's, so the app with the better star average is not the one people write more warmly about.

Both ship on a similar rhythm, roughly every 6 months. Both last shipped on October 23, 2026.

## The numbers

| Metric | AO Surgery Reference | Multiplier |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (14 ratings)](https://appshunter.io/ios/app/ao-surgery-reference/id403961165/reviews) | **[4.6 (24 ratings)](https://appshunter.io/ios/app/multiplier/id460335161/reviews)** |
| Number of ratings | 14 | **24** |
| Positive reviews | **85.8% of reviews** | 83.3% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | Every 6 months |
| Monetization | **Free** | Paid |
| Size | 1 MB | 62 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 12+ |
| Developer | [AO Foundation](https://appshunter.io/developer/399757056) | [LifeBridge Health](https://appshunter.io/developer/460335164) |

## What reviewers say

### AO Surgery Reference

[App page](https://appshunter.io/ios/app/ao-surgery-reference/id403961165)

Access a comprehensive online repository of surgical knowledge for fracture management. It provides detailed guidance on diagnosis, treatment, and aftercare for numerous fracture types, supported by extensive illustrations and expert review.

**Highlights:** 353 fracture types covered, 172 surgical approaches, 1222 surgical procedures, Over 30,000 illustrations, Feline, canine, and equine fracture care, Powerful search function

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Multiplier

[App page](https://appshunter.io/ios/app/multiplier/id460335161)

This app automates complex calculations for predicting mature height, bone length, and limb length discrepancies in children. It simplifies manual methods, reducing calculation time and errors for various orthopedic and growth-related assessments.

**Highlights:** Predict mature height, Calculate bone length, Assess limb length discrepancy, Analyze growth remaining, Plot height on CDC charts, Scanogram calculations, Foot length analysis

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is AO Surgery Reference free?

AO Surgery Reference is free to download, with no in-app purchases.

### Is Multiplier free?

Multiplier is free to download, with no in-app purchases.

### Which has better reviews, AO Surgery Reference or Multiplier?

Multiplier is rated higher. AO Surgery Reference averages 4.4 out of 5 from 14 ratings, while Multiplier averages 4.6 from 24 ratings.

### Do AO Surgery Reference or Multiplier have ads?

Neither AO Surgery Reference nor Multiplier shows ads.

### Which is updated more often, AO Surgery Reference or Multiplier?

AO Surgery Reference ships an update every 6 months, and Multiplier every 6 months. Most recently, AO Surgery Reference was updated on October 23, 2026 and Multiplier on October 23, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*