# iOX vs Flutter

The clearest difference is review sentiment: Flutter at 100% against iOX's 35%. Flutter also leads on rating (5.0 vs 2.8) and update cadence (every 3 weeks vs every 2 months). iOX's advantage is in-app purchases (none vs 3) and ratings volume (15 vs 2). On price, ads and device support there is nothing between them.

Both are free to download. Flutter sells 3 in-app purchases, starting at $14.99 per month. iOX asks for nothing beyond the download.

Flutter holds the better App Store score, 5.0 against 2.8. That said, the two scores are not equally well evidenced: iOX has 15 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 35% of iOX's written reviews are positive against 100% of Flutter's.

iOX ships an update every 2 months, Flutter every 3 weeks. The most recent releases landed on October 2, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | iOX | Flutter |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.8 (15 ratings)](https://appshunter.io/ios/app/iox/id957603710/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/flutter-heartbeat-sync-app/id6758436973/reviews)** |
| Number of ratings | **15** | 2 |
| Positive reviews | 35.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | **Free** | Subscription |
| Size | 6 MB | 21 MB |
| Requires iOS | **12.0** | 17.6 |
| Devices | iPhone, iPod | iPhone, Apple Watch |
| Age rating | 17+ | 4+ |
| Developer | [Net 1688, Inc.](https://appshunter.io/developer/957603709) | [CYBERIAN TECHNOLOGIES LLC](https://appshunter.io/developer/1872937842) |

## What reviewers say

### iOX

[App page](https://appshunter.io/ios/app/iox/id957603710)

This app helps manage your personal health by noninvasively tracking blood oxygenation, heart rate, and perfusion index. It features a plethysmograph display and programmable alarms for health alerts. Data can be easily exported for review.

**Highlights:** Noninvasive SpO2 tracking, Heart rate monitoring, Perfusion index tracking, Plethysmograph display, Programmable alarms, One-click CSV data export

**Features:** macOS Compatibility

**In-app purchases:** none


### Flutter

[App page](https://appshunter.io/ios/app/flutter-heartbeat-sync-app/id6758436973)

Experience your heartbeat as a live haptic sensation on your wrist. Connect with loved ones by sharing real-time heartbeats, fostering a sense of presence and intimacy across any distance. Choose from various haptic styles for a personalized and calming experience.

**Highlights:** Live haptic heartbeat feedback on Apple Watch, Solo Sync for personal awareness, Partner Sync for sharing with others, Real-time BPM display, Multiple haptic pulse styles, Invite-based partner pairing

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Partner Sync (Monthly) | $14.99 | per month |
| Partner Sync Quarterly | $39.99 | per 3 months |
| Partner Sync Annual | $119.99 | per year |


## Frequently asked questions

### Is iOX free?

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

### Is Flutter free?

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

### Which has better reviews, iOX or Flutter?

Flutter is rated higher. iOX averages 2.8 out of 5 from 15 ratings, while Flutter averages 5.0 from 2 ratings.

### Do iOX or Flutter have ads?

Neither iOX nor Flutter shows ads.

### Which is updated more often, iOX or Flutter?

iOX ships an update every 2 months, and Flutter every 3 weeks. Most recently, iOX was updated on October 2, 2026 and Flutter on September 22, 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.*