# CORE Thermal Sensor vs Fuelin

The clearest difference is rating: Fuelin at 4.5 against CORE Thermal Sensor's 2.5. Fuelin also leads on review sentiment (51% vs 19%) and update cadence (every 10 days vs every 2 months). CORE Thermal Sensor's advantage is in-app purchases (none vs 5) and ads (none vs shown). On price and iOS requirement there is nothing between them.

Both are free to download. Fuelin sells 5 in-app purchases, starting at $29.00 per month. CORE Thermal Sensor asks for nothing beyond the download.

Fuelin holds the better App Store score, 4.5 against 2.5. That said, the two scores are not equally well evidenced: Fuelin has 1.3K ratings behind it against 35, so its average is the more settled of the two. Written reviews point the same way: 19% of CORE Thermal Sensor's written reviews are positive against 51% of Fuelin's.

CORE Thermal Sensor ships an update every 2 months, Fuelin every 10 days. The most recent releases landed on November 3, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | CORE Thermal Sensor | Fuelin |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.5 (35 ratings)](https://appshunter.io/ios/app/core-thermal-sensor/id1521866309/reviews) | **[4.5 (1.3K ratings)](https://appshunter.io/ios/app/fuelin-performance-nutrition/id1579806995/reviews)** |
| Number of ratings | 35 | **1.3K** |
| Positive reviews | 18.8% of reviews | **50.5% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Every 10 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 55 MB | 87 MB |
| Requires iOS | **15.1** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [greenteg AG](https://appshunter.io/developer/1510577388) | [Thrive AI Labs](https://appshunter.io/developer/1574246908) |

## What reviewers say

### 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


### Fuelin

[App page](https://appshunter.io/ios/app/fuelin-performance-nutrition/id1579806995)

This app provides personalized sports nutrition plans for athletes, adapting daily calorie and macro targets to workouts and goals. It offers smart meal recommendations, workout fueling guidance, and body composition management. Log food easily via voice, text, or barcode scanning.

**Highlights:** Personalized daily nutrition targets, Workout and race fueling guidance, Smart meal and portion recommendations, AI-powered food logging, Body composition management, Workout integration with popular platforms, Hydration and gut training tools

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Autopilot Monthly Plan | $29.00 | per month |
| Copilot Monthly | $99.00 | per month |
| Autopilot Yearly Plan | $139.00 | per year |
| Autopilot Yearly | $139.00 | per year |
| Copilot Yearly | $399.00 | per year |


## Frequently asked questions

### Is CORE Thermal Sensor free?

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

### Is Fuelin free?

Fuelin is free to download, with in-app purchases available.

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

Fuelin is rated higher. CORE Thermal Sensor averages 2.5 out of 5 from 35 ratings, while Fuelin averages 4.5 from 1.3K ratings.

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

Fuelin shows ads; CORE Thermal Sensor does not.

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

CORE Thermal Sensor ships an update every 2 months, and Fuelin every 10 days. Most recently, CORE Thermal Sensor was updated on November 3, 2026 and Fuelin on November 7, 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.*