# COE Prep vs AAO eBooks

The clearest difference is review sentiment: COE Prep at 76% against AAO eBooks's 18%. COE Prep also leads on rating (4.8 vs 3.8) and update cadence (every 3 weeks vs every 3 months). AAO eBooks's advantage is in-app purchases (none vs 1). On price, ads and device support there is nothing between them.

Both are free to download. COE Prep sells 1 one-off in-app purchase. AAO eBooks asks for nothing beyond the download.

COE Prep holds the better App Store score, 4.8 against 3.8. That said, the two scores are not equally well evidenced: COE Prep has 78 ratings behind it against 5, so its average is the more settled of the two. Written reviews point the same way: 76% of COE Prep's written reviews are positive against 18% of AAO eBooks's.

COE Prep ships an update every 3 weeks, AAO eBooks every 3 months. The most recent releases landed on September 19, 2026 and June 6, 2026 respectively.

## The numbers

| Metric | COE Prep | AAO eBooks |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (78 ratings)](https://appshunter.io/ios/app/coe-prep/id315534299/reviews)** | [3.8 (5 ratings)](https://appshunter.io/ios/app/aao-ebooks/id665817219/reviews) |
| Number of ratings | **78** | 5 |
| Positive reviews | **76.2% of reviews** | 18.2% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 121 MB | 78 MB |
| Requires iOS | **10.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Higher Learning Technologies](https://appshunter.io/developer/571804544) | [American Academy of Ophthalmology, Inc.](https://appshunter.io/developer/665817223) |

## What reviewers say

### COE Prep

[App page](https://appshunter.io/ios/app/coe-prep/id315534299)

Prepare for your Certified Ophthalmic Executive exam with official flashcards. This app offers over 300 practice questions covering key areas of ophthalmic administration, with detailed explanations and progress tracking. Study efficiently anytime, anywhere.

**Highlights:** 300+ exam-like practice questions, Detailed explanations for answers, Covers 6 key exam categories, Tag questions for quick review, Immediate progress feedback, Study anytime, anywhere

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| COE Exam Prep | $99.99 | one-time |


### AAO eBooks

[App page](https://appshunter.io/ios/app/aao-ebooks/id665817219)

Access essential ophthalmology textbooks on your mobile device. Search, browse, and download purchased eBooks for offline use. Enhance learning with notes, highlights, and CME credit opportunities.

**Highlights:** Access purchased eBooks, Offline reading capability, Search and browse content, Highlighting and note-taking, Bookmark functionality, Earn CME credits

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is COE Prep free?

COE Prep is free to download, with in-app purchases available.

### Is AAO eBooks free?

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

### Which has better reviews, COE Prep or AAO eBooks?

COE Prep is rated higher. COE Prep averages 4.8 out of 5 from 78 ratings, while AAO eBooks averages 3.8 from 5 ratings.

### Do COE Prep or AAO eBooks have ads?

Neither COE Prep nor AAO eBooks shows ads.

### Which is updated more often, COE Prep or AAO eBooks?

COE Prep ships an update every 3 weeks, and AAO eBooks every 3 months. Most recently, COE Prep was updated on September 19, 2026 and AAO eBooks on June 6, 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.*