# OpenCap vs Knee Injury Tracker

The clearest difference is in-app purchases: OpenCap at none against Knee Injury Tracker's 8. OpenCap also leads on iOS requirement (15.6 vs 17.0). Knee Injury Tracker's advantage is update cadence (every 4 days vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. Knee Injury Tracker sells 7 one-off in-app purchases. OpenCap asks for nothing beyond the download.

OpenCap ships an update every 4 months, Knee Injury Tracker every 4 days. The most recent releases landed on October 25, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | OpenCap | Knee Injury Tracker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (7 ratings)](https://appshunter.io/ios/app/opencap/id1630513242/reviews)** | — |
| Number of ratings | **7** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 days** |
| Monetization | Free | — |
| Size | 6 MB | 199 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Model Health, Inc.](https://appshunter.io/developer/1252127888) | [FlexiTrace Yazilim Ticaret LIMITED SIRKETI](https://appshunter.io/developer/1703528817) |

## What reviewers say

### OpenCap

[App page](https://appshunter.io/ios/app/opencap/id1630513242)

Capture 3D human movement data using your iOS device's camera. Analyze biomechanics through a comprehensive system including an app, web platform, and cloud computing.

**Highlights:** 3D human movement capture, iOS video recording, Web-based data collection, Biomechanical analysis, Cloud computing integration

**Features:** Vision Pro support

**In-app purchases:** none


### Knee Injury Tracker

[App page](https://appshunter.io/ios/app/knee-injury-tracker/id6748382534)

**Features:** macOS Compatibility

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 5 Coins | $9.99 | one-time |
| 10 Coins | $17.99 | one-time |
| 1 Coin | $29.99 | one-time |
| 5 Coins | $69.99 | one-time |
| 4 Coins | $98.99 | one-time |
| 10 coin pack | $119.00 | one-time |
| 10 Coins | $191.99 | one-time |


## Frequently asked questions

### Is OpenCap free?

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

### Is Knee Injury Tracker free?

Knee Injury Tracker is free to download, with in-app purchases available.

### Do OpenCap or Knee Injury Tracker have ads?

Neither OpenCap nor Knee Injury Tracker shows ads.

### Which is updated more often, OpenCap or Knee Injury Tracker?

OpenCap ships an update every 4 months, and Knee Injury Tracker every 4 days. Most recently, OpenCap was updated on October 25, 2026 and Knee Injury Tracker on October 2, 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.*