# The narnar app vs Coltrain

The clearest difference is rating: Coltrain at 5.0 against The narnar app's 4.8. Coltrain also leads on update cadence (monthly vs every 3 months) and device support (3 vs 1). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Coltrain holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 8 and 17 respectively.

The narnar app ships an update every 3 months, Coltrain monthly. The most recent releases landed on October 16, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | The narnar app | Coltrain |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (8 ratings)](https://appshunter.io/ios/app/the-narnar-app/id1338238999/reviews) | **[5.0 (17 ratings)](https://appshunter.io/ios/app/coltrain/id1491315335/reviews)** |
| Number of ratings | 8 | **17** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | Free | Free |
| Size | 13 MB | 302 MB |
| Requires iOS | **14.3** | 15.6 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 12+ | 17+ |
| Developer | [narnar, LLC](https://appshunter.io/developer/1058713005) | [Cognition Med, LLC](https://appshunter.io/developer/1491315334) |

## What reviewers say

### The narnar app

[App page](https://appshunter.io/ios/app/the-narnar-app/id1338238999)

This application aids researchers in processing and quantifying perfusion studies for contrast-enhanced ultrasound. It supports various organs and research protocols, offering real-time analysis of microvascular blood flow.

**Highlights:** Perfusion study processing, Quantification of microvascular blood flow, Supports various organs and research protocols, Automatic and manual image alignment, Real-time time-videointensity curve analysis, Parametric imaging of blood flow

**Features:** macOS Compatibility

**In-app purchases:** none


### Coltrain

[App page](https://appshunter.io/ios/app/coltrain/id1491315335)

A secure, cloud-based messaging platform for healthcare professionals to enhance patient care and collaboration. It allows for case-based discussions and the secure sharing of photos, videos, and documents.

**Highlights:** HIPAA-compliant messaging, Secure cloud-based platform, Case-based discussions, Photo and document sharing, Peer-to-peer communication, Mobile device compatibility

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is The narnar app free?

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

### Is Coltrain free?

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

### Which has better reviews, The narnar app or Coltrain?

Coltrain is rated higher. The narnar app averages 4.8 out of 5 from 8 ratings, while Coltrain averages 5.0 from 17 ratings.

### Do The narnar app or Coltrain have ads?

Neither The narnar app nor Coltrain shows ads.

### Which is updated more often, The narnar app or Coltrain?

The narnar app ships an update every 3 months, and Coltrain monthly. Most recently, The narnar app was updated on October 16, 2026 and Coltrain on October 5, 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.*