OpenCap vs Knee Injury Tracker
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OpenCap
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.
- 3D human movement capture
- iOS video recording
- Web-based data collection
- Biomechanical analysis
- Cloud computing integration
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OpenCap is a software system to measure 3D human movement from iOS device videos. It comprises an iOS app for video capture, a web app for data collection and visualization, and scalable cloud computing for biomechanical analysis from video.
Knee Injury Tracker
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Knee Injury Tracker is an AI-powered Knee Tracker app that transforms how healthcare professionals evaluate movement and monitor knee health—no markers, sensors, or wearables required. Designed for physiotherapists, sports professionals, and rehab experts, Knee Injury Tracker provides real-time, in-depth analysis of key knee movement parameters using just a smartphone camera. 1. AI Knee Tracking and kinematic Analysis Knee Injury Tracker advanced knee tracking technology captures precise knee motion and delivers intuitive, easy-to-understand insights. The app measures: Step length, step time, and knee movement symmetry Cadence and step count Time spent in Stance vs. swing phases Progression of knee recovery over time All data is presented with clean, exportable graphs and detailed PDF reports, making it easy to document patient progress or share with colleagues. Supports a wide range of knee injuries and conditions: ACL (Anterior Cruciate Ligament) PCL (Posterior Cruciate Ligament) MCL (Medial Collateral Ligament) LCL (Lateral Collateral Ligament) Post-operative rehabilitation General knee instability and overuse injuries The app provides objective data to guide treatment planning, track progress, and optimize recovery strategies. 2. Real-Time Range of Motion (ROM) Tracking Assess knee flexibility and mobility with live angular reports: Range of Motion Angular Velocity Ideal for monitoring rehab progress and customizing therapy plans. Your privacy comes first. Terms of Use: [https://flexitrace.com/terms&conditions.html]
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | OpenCap | Knee Injury Tracker |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (7 ratings) — better | — |
| Number of ratings | 7 — better | — |
| Update frequency | Every 4 months | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 17.0 |
| Further details — not scored | ||
| Size | 6 MB | 199 MB |
| Age rating | 4+ | 4+ |
| Developer | Model Health, Inc. | FlexiTrace Yazilim Ticaret LIMITED SIRKETI |
In-app purchases
OpenCap
No in-app purchases
Knee Injury Tracker
- 5 Coins$9.99
- 10 Coins2 variants$17.99
- 1 Coin$29.99
Show 4 moreShow fewer
- 5 Coins$69.99
- 4 Coins$98.99
- 10 coin pack$119.00
- 10 Coins$191.99









