# Histamine Intolerance Scanner vs MCAS Tracker

The clearest difference is rating: MCAS Tracker at 4.4 against Histamine Intolerance Scanner's 3.0. MCAS Tracker also leads on ratings volume (21 vs 4) and device support (4 vs 2). Histamine Intolerance Scanner's advantage is in-app purchases (none vs 16) and update cadence (every 3 days vs every 6 months). On price, ads and iOS requirement there is nothing between them.

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

MCAS Tracker holds the better App Store score, 4.4 against 3.0. That said, the two scores are not equally well evidenced: MCAS Tracker has 21 ratings behind it against 4, so its average is the more settled of the two.

Histamine Intolerance Scanner ships an update every 3 days, MCAS Tracker every 6 months. Both last shipped on October 24, 2026.

## The numbers

| Metric | Histamine Intolerance Scanner | MCAS Tracker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (4 ratings)](https://appshunter.io/ios/app/histamine-intolerance-scanner/id1640339997/reviews) | **[4.4 (21 ratings)](https://appshunter.io/ios/app/mcas-tracker/id6754931863/reviews)** |
| Number of ratings | 4 | **21** |
| Positive reviews | — | 75.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 6 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 45 MB | 238 MB |
| Requires iOS | 16.4 | **15.5** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Jeremy Roustang](https://appshunter.io/developer/595131737) | [Digital Therapeutics](https://appshunter.io/developer/1721663167) |

## What reviewers say

### Histamine Intolerance Scanner

[App page](https://appshunter.io/ios/app/histamine-intolerance-scanner/id1640339997)

This app helps you identify ingredients that may cause histamine intolerance. It provides a searchable database of over 1000 ingredients with varying intolerance levels.

**Highlights:** Searchable ingredient database, Over 1000 ingredients listed, Intolerance level indicators, Quick ingredient lookup

**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 Histamine Intolerance Scanner free?

Histamine Intolerance Scanner 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, Histamine Intolerance Scanner or MCAS Tracker?

MCAS Tracker is rated higher. Histamine Intolerance Scanner averages 3.0 out of 5 from 4 ratings, while MCAS Tracker averages 4.4 from 21 ratings.

### Do Histamine Intolerance Scanner or MCAS Tracker have ads?

Neither Histamine Intolerance Scanner nor MCAS Tracker shows ads.

### Which is updated more often, Histamine Intolerance Scanner or MCAS Tracker?

Histamine Intolerance Scanner ships an update every 3 days, and MCAS Tracker every 6 months. Most recently, Histamine Intolerance Scanner was updated on October 24, 2026 and MCAS Tracker 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.*