# eCOA vs O

The clearest difference is rating: eCOA at 5.0 against O's 1.0. eCOA also leads on iOS requirement (13.0 vs 15.0). O's advantage is monetization model (free vs ad-supported) and update cadence (every 2 weeks vs monthly). 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.

eCOA holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

eCOA ships an update monthly, O every 2 weeks. The most recent releases landed on October 24, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | eCOA | O |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/ecoa/id1599236633/reviews)** | [1.0 (1 ratings)](https://appshunter.io/ios/app/o-trial-pro/id1658238794/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Every 2 weeks** |
| Monetization | Ad-supported | **Free** |
| Size | 69 MB | 56 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 17+ | 17+ |
| Developer | [EClinCloud (Shenzhen) Technology Co., Ltd](https://appshunter.io/developer/1572780199) | [铨融 (苏州)医药科技开发有限公司](https://appshunter.io/developer/1253822764) |

## What reviewers say

### eCOA

[App page](https://appshunter.io/ios/app/ecoa/id1599236633)

This app facilitates real-time patient feedback collection during clinical trials. It streamlines the process of gathering accurate patient input to speed up drug development, offering features like easy login and timely reminders.

**Highlights:** Real-time patient feedback, Clinical trial data collection, Patient-centered design, Easy login, User training, Scale completion, Timely reminders

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

**In-app purchases:** none


### O

[App page](https://appshunter.io/ios/app/o-trial-pro/id1658238794)

This app provides an information management solution for clinical trials. It aims to streamline trial processes and data handling for medical professionals. The application is designed for use on iPhones and iPods.

**Highlights:** Clinical trial information management, Streamlined trial processes, Data handling for medical professionals, Mobile solution for iPhone and iPod

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

**In-app purchases:** none


## Frequently asked questions

### Is eCOA free?

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

### Is O free?

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

### Which has better reviews, eCOA or O?

eCOA is rated higher. eCOA averages 5.0 out of 5 from 1 ratings, while O averages 1.0 from 1 ratings.

### Do eCOA or O have ads?

Neither eCOA nor O shows ads.

### Which is updated more often, eCOA or O?

eCOA ships an update monthly, and O every 2 weeks. Most recently, eCOA was updated on October 24, 2026 and O on October 2, 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.*