# Frontier X vs Train.Red APP

The clearest difference is in-app purchases: Train.Red APP at none against Frontier X's 2. Train.Red APP also leads on rating (5.0 vs 4.6). Frontier X's advantage is ratings volume (318 vs 1). On price, update cadence, ads and device support there is nothing between them.

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

Train.Red APP holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Frontier X has 318 ratings behind it against 1, so its average is the more settled of the two.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 26, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | Frontier X | Train.Red APP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (318 ratings)](https://appshunter.io/ios/app/frontier-x/id1483444499/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/trainred-app/id6451237438/reviews)** |
| Number of ratings | **318** | 1 |
| Positive reviews | 81.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Monetization | Free with in-app purchases | **Free** |
| Size | 569 MB | 70 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, Apple Watch | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Fourthfrontier](https://appshunter.io/developer/1331846764) | [Train.Red B.V.](https://appshunter.io/developer/1646391181) |

## 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 monitor. Gain detailed insights into heart rate, rhythms, and training load. Receive personalized feedback and alerts to optimize your workouts and understand your body better.

**Highlights:** Heart Health Monitoring, Real-time Heart Rate & HRV, Breathing Rate & Strain Tracking, Activity Recording (24hrs), Personalized Vibration Alerts, 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


### Train.Red APP

[App page](https://appshunter.io/ios/app/trainred-app/id6451237438)

This app monitors muscle oxygen saturation to provide real-time physiological insights for athletes and coaches. It helps optimize performance, track recovery, and analyze training data with actionable metrics.

**Highlights:** Muscle oxygen saturation monitoring, Real-time physiological insights, Performance and recovery tracking, Workout analysis and data export, Team/organization structure, Live data overlay

**In-app purchases:** none


## Frequently asked questions

### Is Frontier X free?

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

### Is Train.Red APP free?

Train.Red APP is free to download, with no in-app purchases.

### Which has better reviews, Frontier X or Train.Red APP?

Train.Red APP is rated higher. Frontier X averages 4.6 out of 5 from 318 ratings, while Train.Red APP averages 5.0 from 1 ratings.

### Do Frontier X or Train.Red APP have ads?

Neither Frontier X nor Train.Red APP shows ads.

### Which is updated more often, Frontier X or Train.Red APP?

Frontier X ships an update every 3 weeks, and Train.Red APP every 3 weeks. Most recently, Frontier X was updated on October 26, 2026 and Train.Red APP on October 20, 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.*