# Rhythm SYNC. vs byrna

The clearest difference is review sentiment: byrna at 100% against Rhythm SYNC.'s 13%. byrna also leads on rating (5.0 vs 1.8) and update cadence (every 9 days vs every 3 months). Rhythm SYNC.'s advantage is in-app purchases (none vs 2) and ratings volume (128 vs 2). On price, ads and device support there is nothing between them.

Both are free to download. byrna sells 2 in-app purchases, starting at $9.99 per month. Rhythm SYNC. asks for nothing beyond the download.

byrna holds the better App Store score, 5.0 against 1.8. That said, the two scores are not equally well evidenced: Rhythm SYNC. has 128 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 13% of Rhythm SYNC.'s written reviews are positive against 100% of byrna's.

Rhythm SYNC. ships an update every 3 months, byrna every 9 days. The most recent releases landed on October 2, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Rhythm SYNC. | byrna |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.8 (128 ratings)](https://appshunter.io/ios/app/rhythm-sync/id1226606963/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/byrna/id6780986660/reviews)** |
| Number of ratings | **128** | 2 |
| Positive reviews | 13.1% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 9 days** |
| Monetization | **Free** | Freemium |
| Size | 47 MB | 15 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Scosche](https://appshunter.io/developer/340018842) | [AIDEN AUGUST LINDAN BUCK](https://appshunter.io/developer/6780986662) |

## What reviewers say

### Rhythm SYNC.

[App page](https://appshunter.io/ios/app/rhythm-sync/id1226606963)

This app connects to heart rate monitors to display real-time data, manage activity modes, and track workout history. It allows for software updates and integrates with HealthKit for saving workout data.

**Highlights:** Connects to Rhythm 24 and Rhythm+ monitors, Manages activity modes and biometrics, Displays heart rate and battery level, Configures data sharing with other apps, Collects and downloads recorded activities, Performs software and firmware updates, HealthKit integration

**In-app purchases:** none

**What reviewers like**

- ✅ Accurate heart rate readings
- 🔋 Long-lasting device battery life
- 🔄 Reliable device hardware
- 📱 Simple and straightforward interface
- 🔗 Works well with third-party apps (Peloton, Garmin, Apple Watch)

**What reviewers complain about**

- 🐛 Frequent Bluetooth connection failures
- 🐛 App crashes and freezes regularly
- ❌ App doesn't recognize connected devices
- ⚠️ HRV mode difficult or impossible to access
- 📊 Extremely limited app functionality

**Reported bugs**

- App fails to detect device despite Bluetooth connection
- Bluetooth connection drops frequently during workouts
- App crashes on startup (splash screen freeze)
- Firmware update fails repeatedly
- HRV readings not displaying or accessible

**Requested features**

- HRV (Heart Rate Variability) mode that actually works
- Comprehensive workout history and logging
- Data export to multiple health apps (MyFitnessPal, TrainingPeaks, etc.)
- Customizable heart rate zones that persist
- Batch download and export of multiple files


### byrna

[App page](https://appshunter.io/ios/app/byrna/id6780986660)

This AI-powered fitness app creates personalized strength training programs that adapt to your progress. Track your workouts, monitor your strength gains with a unique scoring system, and gain insights into your muscle recovery and nutrition.

**Highlights:** AI-powered adaptive workout programs, Comprehensive workout logging, Byrna Score for strength tracking, Muscle recovery heatmap, Food and supplement logging, Progress analytics

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly Subscription | $9.99 | per month |
| Premium Yearly Subscription | $79.99 | per year |


## Frequently asked questions

### Is Rhythm SYNC. free?

Rhythm SYNC. is free to download, with no in-app purchases.

### Is byrna free?

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

### Which has better reviews, Rhythm SYNC. or byrna?

byrna is rated higher. Rhythm SYNC. averages 1.8 out of 5 from 128 ratings, while byrna averages 5.0 from 2 ratings.

### Do Rhythm SYNC. or byrna have ads?

Neither Rhythm SYNC. nor byrna shows ads.

### Which is updated more often, Rhythm SYNC. or byrna?

Rhythm SYNC. ships an update every 3 months, and byrna every 9 days. Most recently, Rhythm SYNC. was updated on October 2, 2026 and byrna on October 3, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*