# Frontier X vs Nix Solo

The clearest difference is review sentiment: Frontier X at 82% against Nix Solo's 14%. Frontier X also leads on ratings volume (318 vs 68). Nix Solo's advantage is in-app purchases (none vs 2) and rating (4.8 vs 4.6). On price, update cadence, ads and iOS requirement there is nothing between them.

Both are free to download. Frontier X sells 2 in-app purchases, starting at $14.99 per month. Nix Solo asks for nothing beyond the download.

Nix Solo holds the better App Store score, 4.8 against 4.6. Both are backed by a comparable volume of ratings — 318 and 68 respectively. Written reviews complicate that: 82% of Frontier X's written reviews are positive against 14% of Nix Solo's, so the app with the better star average is not the one people write more warmly about.

Frontier X ships an update every 2 weeks, Nix Solo every 10 days. Both last shipped on November 3, 2026.

## The numbers

| Metric | Frontier X | Nix Solo |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (318 ratings)](https://appshunter.io/ios/app/frontier-x/id1483444499/reviews) | **[4.8 (68 ratings)](https://appshunter.io/ios/app/nix-solo/id1632680170/reviews)** |
| Number of ratings | **318** | 68 |
| Positive reviews | **81.8% of reviews** | 14.3% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 10 days** |
| Monetization | Freemium | **Free** |
| Size | 569 MB | 65 MB |
| Requires iOS | 16.0 | **15.1** |
| Devices | iPhone, Apple Watch | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Fourth Frontier Technologies Private Limited](https://appshunter.io/developer/1331846764) | [Nix, Inc.](https://appshunter.io/developer/1625732872) |

## What reviewers say

### Frontier X

[App page](https://appshunter.io/ios/app/frontier-x/id1483444499)

Track your heart health and exercise performance with a smart chest strap wearable. Get detailed insights into heart rate, HRV, strain, and more, with personalized training feedback and alerts. Integrates with other devices and offers advanced analytics through a premium subscription.

**Highlights:** Heart health and performance tracking, Real-time heart rate and HRV monitoring, Personalized vibration alerts, Activity recording up to 24 hours, Integration with Bluetooth wearables, AI-enabled training insights, Metabolic Profile Analytics (Premium)

**Features:** Apple Watch app

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $14.99 | per month |
| Yearly | $119.99 | per year |

**What reviewers like**

- 🚀 Amazing device
- 👍 Great HR data and insight
- 👍 Helpful in gaining more data
- 👍 Fantastic concept with excellent execution
- 👍 Loads of useful information

**What reviewers complain about**

- 🐛 Worse and worse as time goes by
- 🐛 ECG doesn't work
- 🐛 Chest strap issues, device keeps popping out
- 🐛 Paywalled functionality
- 🐛 Syncing issues, device keeps disconnecting

**Reported bugs**

- ECG stopped working
- Inaccurate breathing rate and other metrics
- Inability to edit activity details for indoor workouts
- Syncing issues with Garmin devices after firmware updates

**Requested features**

- Add interval markers
- Improve integration with Apple Fitness/Fitness+
- Add support for ANT+
- Improve compatibility with other fitness apps and devices
- Add more customization options for workouts


### Nix Solo

[App page](https://appshunter.io/ios/app/nix-solo/id1632680170)

Monitor personal fluid and electrolyte losses in real-time during workouts. This app provides insights into sweat composition and hydration needs based on individual biology, using data from a companion biosensor.

**Highlights:** Real-time fluid and electrolyte loss monitoring, Personalized sweat composition insights, Correlates sweat data with environmental factors (Nix Index), Post-workout Sweat Intelligence reports, Integration with Apple Watch and Garmin devices, Workout type and hydration input

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

**In-app purchases:** none


## Frequently asked questions

### Is Frontier X free?

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

### Is Nix Solo free?

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

### Which has better reviews, Frontier X or Nix Solo?

Nix Solo is rated higher. Frontier X averages 4.6 out of 5 from 318 ratings, while Nix Solo averages 4.8 from 68 ratings.

### Do Frontier X or Nix Solo have ads?

Neither Frontier X nor Nix Solo shows ads.

### Which is updated more often, Frontier X or Nix Solo?

Frontier X ships an update every 2 weeks, and Nix Solo every 10 days. Most recently, Frontier X was updated on November 3, 2026 and Nix Solo on November 3, 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.*