# HRV4Training vs sleep² sleeptracker & analysis

The clearest difference is price: sleep² sleeptracker & analysis at Free against HRV4Training's $9.99. sleep² sleeptracker & analysis also leads on update cadence (every 3 weeks vs every 2 months). HRV4Training's advantage is in-app purchases (none vs 4) and chart position (#31 vs unranked). On rating, review sentiment, ads and device support there is nothing between them.

sleep² sleeptracker & analysis is free to download; HRV4Training costs $9.99 up front. sleep² sleeptracker & analysis sells 4 in-app purchases, starting at $9.99 per month. HRV4Training asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 3.6 for HRV4Training against 3.5 for sleep² sleeptracker & analysis. That said, the two scores are not equally well evidenced: HRV4Training has 290 ratings behind it against 38, so its average is the more settled of the two. Written reviews are what separate them: 61% of HRV4Training's written reviews are positive against 64% of sleep² sleeptracker & analysis's.

HRV4Training ships an update every 2 months, sleep² sleeptracker & analysis every 3 weeks. Both last shipped on November 12, 2026.

## The numbers

| Metric | HRV4Training | sleep² sleeptracker & analysis |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[3.6 (290 ratings)](https://appshunter.io/ios/app/hrv4training/id686923970/reviews)** | [3.5 (38 ratings)](https://appshunter.io/ios/app/sleep-sleeptracker-and-analysis/id1629426238/reviews) |
| Number of ratings | **290** | 38 |
| Positive reviews | 60.9% of reviews | **63.6% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Paid | **Free with in-app purchases** |
| Best chart rank | **#31** | — |
| Size | 44 MB | 110 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [A.S.M.A. B.V.](https://appshunter.io/developer/1066843463) | [Nukkuaa](https://appshunter.io/developer/1629426240) |

## What reviewers say

### HRV4Training

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

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

Optimize your training and recovery with daily insights based on a 1-minute morning measurement. This app uses your phone camera or external sensors to track HRV and stress, providing tailored advice to adapt your physical condition.

**Highlights:** 1-minute morning HRV measurement, Phone camera or external sensor compatible, Daily training adaptation advice, Sleep, stress, and lifestyle tagging, Long-term HRV trend analysis, VO2max estimation, Data export and integrations

**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


### sleep² sleeptracker & analysis

[App page](https://appshunter.io/ios/app/sleep-sleeptracker-and-analysis/id1629426238)

This app acts as a personal guide to better sleep, combining innovative sleep training with precise sleep tracking and analysis. It offers an EU-approved medical device program for acute sleep disorders like insomnia, providing personalized recommendations and sleep training based on your data.

**Highlights:** Sleep tracking and analysis, Sleep training programs, Personalized recommendations, Interactive chatbot, Data import (Polar sensor, Apple Health), Manual sleep diary entry

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| sleep² PRO | $9.99 | per month |
| sleep² PRO | $79.99 | per year |
| sleep² intensive program | $39.99 | one-time |
| sleep² intensive program | $99.99 | one-time |


## Frequently asked questions

### Is HRV4Training free?

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

### Is sleep² sleeptracker & analysis free?

sleep² sleeptracker & analysis is free to download, with in-app purchases available.

### Which has better reviews, HRV4Training or sleep² sleeptracker & analysis?

HRV4Training is rated higher. HRV4Training averages 3.6 out of 5 from 290 ratings, while sleep² sleeptracker & analysis averages 3.5 from 38 ratings.

### Do HRV4Training or sleep² sleeptracker & analysis have ads?

Neither HRV4Training nor sleep² sleeptracker & analysis shows ads.

### Which is updated more often, HRV4Training or sleep² sleeptracker & analysis?

HRV4Training ships an update every 2 months, and sleep² sleeptracker & analysis every 3 weeks. Most recently, HRV4Training was updated on November 12, 2026 and sleep² sleeptracker & analysis on November 12, 2026.

---

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