# Heart Histogram vs MCAS Tracker

The clearest difference is rating: MCAS Tracker at 4.5 against Heart Histogram's 4.0. MCAS Tracker also leads on ratings volume (18 vs 2) and device support (4 vs 1). Heart Histogram's advantage is in-app purchases (none vs 16) and review sentiment (100% vs 75%). On price, update cadence and ads there is nothing between them.

Both are free to download. MCAS Tracker sells 16 in-app purchases, starting at $4.95 per month. Heart Histogram asks for nothing beyond the download.

MCAS Tracker holds the better App Store score, 4.5 against 4.0. That said, the two scores are not equally well evidenced: MCAS Tracker has 18 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 100% of Heart Histogram's written reviews are positive against 75% of MCAS Tracker's, so the app with the better star average is not the one people write more warmly about.

Heart Histogram ships an update every 12 months, MCAS Tracker every 6 months. The most recent releases landed on August 20, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Heart Histogram | MCAS Tracker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.0 (2 ratings)](https://appshunter.io/ios/app/heart-histogram/id1451382986/reviews) | **[4.5 (18 ratings)](https://appshunter.io/ios/app/mcas-tracker/id6754931863/reviews)** |
| Number of ratings | 2 | **18** |
| Positive reviews | **100.0% of reviews** | 75.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 12 months | **Every 6 months** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 0 MB | 238 MB |
| Requires iOS | 17.0 | **15.5** |
| Devices | iPhone | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 12+ | 4+ |
| Developer | [Real World Technology Solutions](https://appshunter.io/developer/588275532) | [Digital Therapeutics](https://appshunter.io/developer/1721663167) |

## What reviewers say

### Heart Histogram

[App page](https://appshunter.io/ios/app/heart-histogram/id1451382986)

Visualize your heart rate patterns with detailed histograms. This app analyzes data from your Apple Watch and Health Data to show heart beat frequency at various rates. Customize the time period and filter by activity status.

**Highlights:** Heart rate frequency visualization, Apple Watch data integration, Health Data analysis, Customizable time periods, Activity status filtering

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### MCAS Tracker

[App page](https://appshunter.io/ios/app/mcas-tracker/id6754931863)

This app helps individuals manage Mast Cell Activation Syndrome by tracking symptoms, food intake, and environmental triggers. It offers advanced analytics to identify patterns and provides secure, exportable reports for healthcare providers. The app aims to offer clarity and actionable insights for better health management.

**Highlights:** Symptom tracking (hives, itching, flushing), Food and supplement logging, Trigger identification (environmental, emotional), Advanced analytics and correlation analysis, Medication tracking, Daily health journal, Secure, exportable reports

**Features:** macOS Compatibility, Siri integration, Apple Watch app, iMessage stickers, Vision Pro support

**In-app purchases (16)**

| Purchase | Price | Billing |
| --- | --- | --- |
| flex pass | $4.95 | per month |
| easy pass | $7.99 | per 7 days |
| flex pass | $12.99 | per month |
| carey ai max | $19.99 | per month |
| yearly access | $19.99 | per year |
| smart pass | $19.99 | per year |
| carey ai ultra | $29.99 | per month |
| plus | $29.99 | per year |
| limited discount | $34.99 | per year |
| Premium Yearly | $34.99 | per year |
| yearly access | $39.99 | per year |
| Extended Trial | $39.99 | per year |
| full access | $49.99 | per year |
| store credit | $1.99 | one-time |
| carey ai credits | $8.99 | one-time |
| lifetime upgrade | $119.99 | one-time |


## Frequently asked questions

### Is Heart Histogram free?

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

### Is MCAS Tracker free?

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

### Which has better reviews, Heart Histogram or MCAS Tracker?

MCAS Tracker is rated higher. Heart Histogram averages 4.0 out of 5 from 2 ratings, while MCAS Tracker averages 4.5 from 18 ratings.

### Do Heart Histogram or MCAS Tracker have ads?

Neither Heart Histogram nor MCAS Tracker shows ads.

### Which is updated more often, Heart Histogram or MCAS Tracker?

Heart Histogram ships an update every 12 months, and MCAS Tracker every 6 months. Most recently, Heart Histogram was updated on August 20, 2026 and MCAS Tracker on September 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.*