# US MSK vs Dortop

The clearest difference is in-app purchases: Dortop at none against US MSK's 2. US MSK's advantage is update cadence (every 6 weeks vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

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

US MSK ships an update every 6 weeks, Dortop every 3 months. The most recent releases landed on October 4, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | US MSK | Dortop |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 3 months |
| Monetization | Free with in-app purchases | — |
| Size | 31 MB | 43 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Azul Systems](https://appshunter.io/developer/1460850225) | [Regenerar Servicos Medicos Unipessoal Ltda](https://appshunter.io/developer/1766791502) |

## 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 |


### Dortop

[App page](https://appshunter.io/ios/app/dortop/id6670567751)

**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 Dortop free?

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

### Do US MSK or Dortop have ads?

Neither US MSK nor Dortop shows ads.

### Which is updated more often, US MSK or Dortop?

US MSK ships an update every 6 weeks, and Dortop every 3 months. Most recently, US MSK was updated on October 4, 2026 and Dortop on October 6, 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.*