# iOX vs Cardiac Diagnosis

The clearest difference is review sentiment: Cardiac Diagnosis at 100% against iOX's 35%. Cardiac Diagnosis also leads on rating (4.2 vs 2.8) and update cadence (every 3 weeks vs every 2 months). iOX's advantage is in-app purchases (none vs 4) and ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. Cardiac Diagnosis sells 4 in-app purchases, starting at $0.99 per month. iOX asks for nothing beyond the download.

Cardiac Diagnosis holds the better App Store score, 4.2 against 2.8. Both are backed by a comparable volume of ratings — 15 and 5 respectively. Written reviews point the same way: 35% of iOX's written reviews are positive against 100% of Cardiac Diagnosis's.

iOX ships an update every 2 months, Cardiac Diagnosis every 3 weeks. Both last shipped on October 24, 2026.

## The numbers

| Metric | iOX | Cardiac Diagnosis |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.8 (15 ratings)](https://appshunter.io/ios/app/iox/id957603710/reviews) | **[4.2 (5 ratings)](https://appshunter.io/ios/app/cardiac-diagnosis/id6466367849/reviews)** |
| Number of ratings | **15** | 5 |
| Positive reviews | 35.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 6 MB | 54 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 17+ | 17+ |
| Developer | [Safe Heart USA, Inc.](https://appshunter.io/developer/957603709) | [SUNG DO KIM](https://appshunter.io/developer/1707282337) |

## 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


### Cardiac Diagnosis

[App page](https://appshunter.io/ios/app/cardiac-diagnosis/id6466367849)

This app uses your phone's camera and LED to measure and analyze heart rate and heart rate variability through photoplethysmography. It provides real-time monitoring and allows you to save and view your health data in record and graph formats.

**Highlights:** Heart rate measurement via camera, Heart rate variability analysis, Real-time continuous monitoring, Save and view measurement records, Historical graph view, Data deletion functionality

**Features:** macOS Compatibility

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Subscribe for 1 month | $0.99 | per month |
| Subscribe for 3 months | $1.99 | per 3 months |
| Subscribe for 6 months | $2.99 | per 6 months |
| Subscribe for 1 year | $4.99 | per year |


## Frequently asked questions

### Is iOX free?

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

### Is Cardiac Diagnosis free?

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

### Which has better reviews, iOX or Cardiac Diagnosis?

Cardiac Diagnosis is rated higher. iOX averages 2.8 out of 5 from 15 ratings, while Cardiac Diagnosis averages 4.2 from 5 ratings.

### Do iOX or Cardiac Diagnosis have ads?

Cardiac Diagnosis shows ads; iOX does not.

### Which is updated more often, iOX or Cardiac Diagnosis?

iOX ships an update every 2 months, and Cardiac Diagnosis every 3 weeks. Most recently, iOX was updated on October 24, 2026 and Cardiac Diagnosis on October 24, 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.*