# STF Kronos vs Rex.life

The clearest difference is review sentiment: STF Kronos at 100% against Rex.life's 14%. STF Kronos also leads on rating (4.7 vs 3.3). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

STF Kronos holds the better App Store score, 4.7 against 3.3. Both are backed by a comparable volume of ratings — 9 and 9 respectively. Written reviews point the same way: 100% of STF Kronos's written reviews are positive against 14% of Rex.life's.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 20, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | STF Kronos | Rex.life |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (9 ratings)](https://appshunter.io/ios/app/stf-kronos/id1476804951/reviews)** | [3.3 (9 ratings)](https://appshunter.io/ios/app/rexlife/id6478669848/reviews) |
| Number of ratings | 9 | 9 |
| Positive reviews | **100.0% of reviews** | 14.3% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Free | Free |
| Size | 228 MB | 185 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [STUFFACTORY](https://appshunter.io/developer/1476804950) | [Shenzhen United Power Technology Co., Ltd.](https://appshunter.io/developer/1447215451) |

## What reviewers say

### STF Kronos

[App page](https://appshunter.io/ios/app/stf-kronos/id1476804951)

This app syncs with your smartwatch to monitor your fitness performance across various sports. Track heart rate, steps, and sedentary periods to analyze your health metrics. It offers additional features based on your specific smartwatch model.

**Highlights:** Smartwatch synchronization, Sports performance monitoring, Heart rate tracking, Step counting, Sedentary period analysis, iOS Health App integration

**Features:** Vision Pro support

**In-app purchases:** none


### Rex.life

[App page](https://appshunter.io/ios/app/rexlife/id6478669848)

This smart sports application tracks your fitness data and health status in real-time. It offers personalized exercise plans, holistic wellness support, and convenient workout tracking to help you achieve your health goals.

**Highlights:** Real-time health and activity monitoring, Personalized exercise plans, Holistic wellness support, At-home workouts, Sedentary reminders, Bluetooth device compatibility

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

**In-app purchases:** none


## Frequently asked questions

### Is STF Kronos free?

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

### Is Rex.life free?

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

### Which has better reviews, STF Kronos or Rex.life?

STF Kronos is rated higher. STF Kronos averages 4.7 out of 5 from 9 ratings, while Rex.life averages 3.3 from 9 ratings.

### Do STF Kronos or Rex.life have ads?

Neither STF Kronos nor Rex.life shows ads.

### Which is updated more often, STF Kronos or Rex.life?

STF Kronos ships an update every 2 months, and Rex.life every 2 months. Most recently, STF Kronos was updated on September 20, 2026 and Rex.life on September 21, 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.*