# N4x4 vs Stellar Intervals

The clearest difference is ads: N4x4 at none against Stellar Intervals's shown. Stellar Intervals's advantage is iOS requirement (15.1 vs 17.5). On price, in-app purchases and device support there is nothing between them.

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

## The numbers

| Metric | N4x4 | Stellar Intervals |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (20 ratings)](https://appshunter.io/ios/app/n4x4/id6686407796/reviews)** | — |
| Number of ratings | **20** | — |
| Positive reviews | 66.7% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 2 days | — |
| Monetization | Free | — |
| Size | 16 MB | 41 MB |
| Requires iOS | 17.5 | **15.1** |
| Devices | iPhone, Apple Watch | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Jan van Rensburg](https://appshunter.io/developer/1688121173) | [Garage Projects AB](https://appshunter.io/developer/6774685578) |

## What reviewers say

### N4x4

[App page](https://appshunter.io/ios/app/n4x4/id6686407796)

This app guides you through high-intensity interval training to improve VO2 max. It uses your heart rate monitor to provide real-time cues for effort and recovery, tracking your progress over time. The app offers voice coaching and reminders to help you build a consistent training habit.

**Highlights:** Real-time heart rate zone guidance, Voice and haptic interval cues, Supports multiple heart rate monitors, Workout progress tracking, Hands-free training mode, Apple Health integration

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

**In-app purchases:** none


### Stellar Intervals

[App page](https://appshunter.io/ios/app/stellar-intervals/id6774685576)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is N4x4 free?

N4x4 is free to download, with no in-app purchases.

### Is Stellar Intervals free?

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

### Do N4x4 or Stellar Intervals have ads?

Stellar Intervals shows ads; N4x4 does not.

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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.*