# Heart Rate Variability Logger vs Intervall

The clearest difference is price: Intervall at Free against Heart Rate Variability Logger's $9.99. Intervall also leads on rating (5.0 vs 3.5). Heart Rate Variability Logger's advantage is update cadence (fortnightly vs every 3 months) and ratings volume (19 vs 1). On ads, in-app purchases and device support there is nothing between them.

Intervall is free to download; Heart Rate Variability Logger costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Intervall holds the better App Store score, 5.0 against 3.5. That said, the two scores are not equally well evidenced: Heart Rate Variability Logger has 19 ratings behind it against 1, so its average is the more settled of the two.

Heart Rate Variability Logger ships an update fortnightly, Intervall every 3 months. The most recent releases landed on October 14, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Heart Rate Variability Logger | Intervall |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [3.5 (19 ratings)](https://appshunter.io/ios/app/heart-rate-variability-logger/id683984776/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/intervall/id6760841694/reviews)** |
| Number of ratings | **19** | 1 |
| Positive reviews | 43.1% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 3 months |
| Monetization | Paid | **Free** |
| Size | 10 MB | 4 MB |
| Requires iOS | **15.6** | 18.0 |
| Devices | **iPhone, iPod, Apple Watch** | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [A.S.M.A. B.V.](https://appshunter.io/developer/1066843463) | [Ruben Musca](https://appshunter.io/developer/1885574171) |

## What reviewers say

### Heart Rate Variability Logger

[App page](https://appshunter.io/ios/app/heart-rate-variability-logger/id683984776)

This app records, plots, and exports heart rate variability data, including time, frequency, and non-linear features. It supports experience sampling, RR-interval correction, and activity/location tracking. Requires a compatible Bluetooth heart rate sensor.

**Highlights:** Record and plot HRV data, Extract time and frequency domain features, Experience sampling for event annotation, Compare multiple recordings, Activity and location tracking, RR-interval correction, Export data for Kubios

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### Intervall

[App page](https://appshunter.io/ios/app/intervall/id6760841694)

Create and run custom interval training routines with a clear, legible timer. This app syncs with Apple Watch to display heart rate and control workouts, and can save data to Apple Health.

**Highlights:** Custom interval workouts, Save and reuse workouts, Large, readable timer, Apple Watch mirroring, Watch controls, Live heart rate display, Apple Health integration

**Features:** macOS Compatibility, Apple Watch app

**In-app purchases:** none


## Frequently asked questions

### Is Heart Rate Variability Logger free?

Heart Rate Variability Logger costs $9.99, with no in-app purchases.

### Is Intervall free?

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

### Which has better reviews, Heart Rate Variability Logger or Intervall?

Intervall is rated higher. Heart Rate Variability Logger averages 3.5 out of 5 from 19 ratings, while Intervall averages 5.0 from 1 ratings.

### Do Heart Rate Variability Logger or Intervall have ads?

Neither Heart Rate Variability Logger nor Intervall shows ads.

### Which is updated more often, Heart Rate Variability Logger or Intervall?

Heart Rate Variability Logger ships an update fortnightly, and Intervall every 3 months. Most recently, Heart Rate Variability Logger was updated on October 14, 2026 and Intervall on October 2, 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.*