HIIT 4x4 vs Phy Robotic
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HIIT 4x4
This app guides you through High Intensity Interval Training (HIIT) workouts using your heart rate as a percentage of your Maximum Heart Rate (MHR). It features a speedometer-style dial to monitor your heart rate zones and provides chimes to keep you in target.
- Heart rate zone monitoring
- Speedometer-style dial
- Warning chimes for out-of-zone heart rate
- Workout history storage via Apple Health
- Customizable MHR calculation
- Structured 4x4 HIIT program
Read full descriptionHide full description
HIIT 4x4 is an Apple Watch exercise monitoring app for High Intensity Interval Training (HIIT). The app sequences exercise between high and low intensity intervals. The intensity of the exercise is measured as a percentage of a person's Maximum Heart Rate (MHR). The HIIT 4x4 intervals are as follows: - 10 minutes warmup at 60% MHR - 4 minutes high intensity at 90% MHR - 3 minutes low intensity at 70% MHR - repeat high-low intervals 4 times (4 high intensity intervals of 4 minutes each = 4x4). HIIT 4x4 uses a speedometer type dial to display heart rate. When the arrow is in the green zone then your heart rate is within the interval target. If the heart rate later falls out of the target range, warning chimes are issued until back in range. Each person's MHR is different, and changes with age. A commonly used formula for MHR is 220 - age in years. A more accurate number can be discovered by using a heart monitor during all out exercise and observing the highest heart rate achieved. HIIT 4x4 stores your workout history using Apple Health. HIIT 4x4 is based on the High Intensity Interval Training 4x4 program developed by the Norwegian University of Science and Technology's Cardiac Exercise Group.
Phy Robotic
This app offers advanced body scanning and movement analysis for wellness professionals. It helps measure posture, identify musculoskeletal imbalances, and visualize results in 3D or augmented reality. Seamlessly integrate data with the Phy platform for comprehensive reporting and personalized movement plans.
- Advanced body scanning
- Posture and movement assessments
- 3D model visualization
- AR mode with 3D replay
- Seamless integration with Phy platform
Read full descriptionHide full description
Unlock the power of advanced posture and movement analysis with Phy Scan. Designed for wellness professionals, physical therapists, and health clinics, the Phy Scan app enables you to measure posture and dynamic movement to improve health and performance. Key Features: Advanced Body Scanning: Perform detailed body scans, capturing millions of data points for analysis. Posture and Movement Assessments: Measure musculoskeletal imbalances and evaluate key movements such as squats and overhead reaches. 3D Model Visualization: Preview a detailed 3D model of the body for posture scans, using intuitive finger gestures to zoom in and out and rotate for a comprehensive view. AR Mode with 3D Replay: Experience an augmented reality mode that allows for 3D replay of recorded movement scans, providing an immersive way to review and analyze performance. Seamless Integration: Preview and upload results directly to the Phy platform for comprehensive report access and movement plans via the Phy Health app.
Screenshots
Verdict
The clearest difference is price: Phy Robotic at Free against HIIT 4x4's $9.99. Phy Robotic also leads on rating (5.0 vs 1.0) and update cadence (every 2 months vs every 5 months). HIIT 4x4's advantage is iOS requirement (15.0 vs 18.0). On ratings volume, ads, in-app purchases 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
Phy Robotic is free to download; HIIT 4x4 costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Phy Robotic holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 2 respectively.
HIIT 4x4 ships an update every 5 months, Phy Robotic every 2 months. The most recent releases landed on October 24, 2026 and October 16, 2026 respectively.
| Parameter | HIIT 4x4 | Phy Robotic |
|---|---|---|
| Price | $9.99 | Free — better |
| Rating | 1.0 (1 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 1 | 2 — better |
| Update frequency | Every 5 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPod, Apple Watch — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 2 MB | 54 MB |
| Age rating | 12+ | 17+ |
| Developer | Eastridge Technology | Phyxd, Inc. |
Customer experience
HIIT 4x4
Phy Robotic
In-app purchases
HIIT 4x4
No in-app purchases
Phy Robotic
No in-app purchases









