# US MSK vs Doc Duty

The clearest difference is in-app purchases: Doc Duty at none against US MSK's 2. US MSK's advantage is iOS requirement (13.0 vs 15.1). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. US MSK sells 2 in-app purchases, starting at $0.99 per month. Doc Duty asks for nothing beyond the download.

US MSK ships an update every 6 weeks, Doc Duty every 3 weeks. The most recent releases landed on October 21, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | US MSK | Doc Duty |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 3 weeks** |
| Monetization | Free with in-app purchases | — |
| Size | 31 MB | 36 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Azul Systems](https://appshunter.io/developer/1460850225) | [GILBERTO ZINN SCHUTZ FILHO](https://appshunter.io/developer/1637909096) |

## What reviewers say

### US MSK

[App page](https://appshunter.io/ios/app/us-msk/id1611606746)

This medical app serves as an atlas for musculoskeletal ultrasound imaging of the upper and lower limbs. It provides detailed visual guidance for diagnostic procedures. The app offers a free trial for its subscription plans.

**Highlights:** Musculoskeletal ultrasound atlas, Upper limb imaging, Lower limb imaging, Diagnostic guidance, Free trial available

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $0.99 | per month |
| Annual | $9.99 | per year |


### Doc Duty

[App page](https://appshunter.io/ios/app/doc-duty/id1637998342)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is US MSK free?

US MSK is free to download, with in-app purchases available.

### Is Doc Duty free?

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

### Do US MSK or Doc Duty have ads?

Neither US MSK nor Doc Duty shows ads.

### Which is updated more often, US MSK or Doc Duty?

US MSK ships an update every 6 weeks, and Doc Duty every 3 weeks. Most recently, US MSK was updated on October 21, 2026 and Doc Duty on October 18, 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.*