# HRV Sync vs Shindo Endurance Training

The clearest difference is in-app purchases: HRV Sync at none against Shindo Endurance Training's 4. HRV Sync also leads on iOS requirement (17.0 vs 26.4). Shindo Endurance Training's advantage is update cadence (every 2 days vs every 2 months). On price, ads and device support there is nothing between them.

Both are free to download. Shindo Endurance Training sells 4 in-app purchases, starting at $12.99 per month. HRV Sync asks for nothing beyond the download.

HRV Sync ships an update every 2 months, Shindo Endurance Training every 2 days. The most recent releases landed on October 7, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | HRV Sync | Shindo Endurance Training |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/hrv-sync/id6756378219/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 days** |
| Monetization | Free | — |
| Size | 1 MB | 28 MB |
| Requires iOS | **17.0** | 26.4 |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [Marcin Naglik](https://appshunter.io/developer/1860354816) | [Aleksandr Kolesnikov](https://appshunter.io/developer/6803141981) |

## What reviewers say

### HRV Sync

[App page](https://appshunter.io/ios/app/hrv-sync/id6756378219)

Effortlessly sync your Heart Rate Variability (HRV) data to the iOS Health app. Connect your fitness account to view HRV trends alongside other health metrics. Prioritizes user privacy with secure token-based login and no data collection.

**Highlights:** One-tap HRV data sync to Health app, View HRV history and trends, Secure OAuth login, Custom date range import, Privacy-focused data handling

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

**In-app purchases:** none


### Shindo Endurance Training

[App page](https://appshunter.io/ios/app/shindo-endurance-training/id6803141979)

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Shindo Pro Monthly | $12.99 | per month |
| Shindo Pro Monthly | $12.99 | per month |
| Shindo Pro Yearly | $109.99 | per year |
| Shindo Pro Yearly | $109.99 | per year |


## Frequently asked questions

### Is HRV Sync free?

HRV Sync is free to download, with no in-app purchases.

### Is Shindo Endurance Training free?

Shindo Endurance Training is free to download, with in-app purchases available.

### Do HRV Sync or Shindo Endurance Training have ads?

Neither HRV Sync nor Shindo Endurance Training shows ads.

### Which is updated more often, HRV Sync or Shindo Endurance Training?

HRV Sync ships an update every 2 months, and Shindo Endurance Training every 2 days. Most recently, HRV Sync was updated on October 7, 2026 and Shindo Endurance Training 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.*