# HRV4Training vs CORE Thermal Sensor

The clearest difference is review sentiment: HRV4Training at 61% against CORE Thermal Sensor's 16%. HRV4Training also leads on rating (3.6 vs 2.5) and chart position (#31 vs unranked). CORE Thermal Sensor's advantage is price (Free vs $9.99). On update cadence, ads, in-app purchases and device support there is nothing between them.

CORE Thermal Sensor is free to download; HRV4Training costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

HRV4Training holds the better App Store score, 3.6 against 2.5. That said, the two scores are not equally well evidenced: HRV4Training has 288 ratings behind it against 35, so its average is the more settled of the two. Written reviews point the same way: 61% of HRV4Training's written reviews are positive against 16% of CORE Thermal Sensor's.

HRV4Training ships an update every 6 weeks, CORE Thermal Sensor every 2 months. The most recent releases landed on October 13, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | HRV4Training | CORE Thermal Sensor |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[3.6 (288 ratings)](https://appshunter.io/ios/app/hrv4training/id686923970/reviews)** | [2.5 (35 ratings)](https://appshunter.io/ios/app/core-thermal-sensor/id1521866309/reviews) |
| Number of ratings | **288** | 35 |
| Positive reviews | **61.2% of reviews** | 15.6% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 2 months |
| Monetization | Paid | **Free** |
| Best chart rank | **#31** | — |
| Size | 35 MB | 55 MB |
| Requires iOS | 15.6 | **15.1** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [A.S.M.A. B.V.](https://appshunter.io/developer/1066843463) | [greenteg AG](https://appshunter.io/developer/1510577388) |

## What reviewers say

### HRV4Training

[App page](https://appshunter.io/ios/app/hrv4training/id686923970)

**Currently charting:** #31 Top Paid · Health & Fitness (US App Store)

Quantify stress, balance training and lifestyle, and improve performance with scientifically validated heart rate variability insights. This app accurately assesses HRV using your phone's camera or compatible devices, offering actionable interpretations for optimizing your training plan.

**Highlights:** HRV-based stress quantification, Training and lifestyle balance, Performance improvement insights, Camera-based HRV assessment, Integration with wearables, Training load analysis, VO2max and Lactate Threshold estimation

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 👍 Accurate HRV measurements
- 🚀 Straightforward and easy to use
- 💡 Provides valuable insights for training and recovery
- 👍 Integrates well with other fitness apps
- 👍 Responsive and helpful developer support

**What reviewers complain about**

- 🐛 Inconsistent readings and technical issues
- 🔒 Requires user account and data sharing
- 🔒 Concerns about data privacy
- 🔋 Drains battery when using camera for measurements

**Reported bugs**

- App crashes frequently, especially with iOS updates
- Syncing issues with Strava, TrainingPeaks, and Apple Health
- Camera-based measurements often unreliable or inconsistent

**Requested features**

- Allow multiple measurements per day
- Improve integration with Apple Watch and other wearables
- Add more customization options and data visualization
- Expand support for non-athletic use cases


### CORE Thermal Sensor

[App page](https://appshunter.io/ios/app/core-thermal-sensor/id1521866309)

This app continuously monitors your core body temperature and thermal strain, providing critical data for heat training and optimal race performance. It helps athletes of all levels improve their training and achieve better results.

**Highlights:** Continuous core body temperature monitoring, Real-time Heat Strain Index, Heat Zones for training and racing, Heat Training Load and Adaptation Score, Passive heat training tracking, Data trends and historical analysis, Connectivity with sports devices

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is HRV4Training free?

HRV4Training costs $9.99, with no in-app purchases.

### Is CORE Thermal Sensor free?

CORE Thermal Sensor is free to download, with no in-app purchases.

### Which has better reviews, HRV4Training or CORE Thermal Sensor?

HRV4Training is rated higher. HRV4Training averages 3.6 out of 5 from 288 ratings, while CORE Thermal Sensor averages 2.5 from 35 ratings.

### Do HRV4Training or CORE Thermal Sensor have ads?

Neither HRV4Training nor CORE Thermal Sensor shows ads.

### Which is updated more often, HRV4Training or CORE Thermal Sensor?

HRV4Training ships an update every 6 weeks, and CORE Thermal Sensor every 2 months. Most recently, HRV4Training was updated on October 13, 2026 and CORE Thermal Sensor 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.*