# Guide AOD vs SURF

The clearest difference is in-app purchases: Guide AOD at none against SURF's 1. Guide AOD also leads on update cadence (every 2 months vs every 5 months) and iOS requirement (9.0 vs 16.0). SURF's advantage is review sentiment (67% vs 33%). On price, ads and device support there is nothing between them.

Both are free to download. SURF sells 1 in-app purchase, starting at $99.99 per year. Guide AOD asks for nothing beyond the download.

Guide AOD ships an update every 2 months, SURF every 5 months. The most recent releases landed on September 12, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Guide AOD | SURF |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 33.3% of reviews | **66.7% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 5 months |
| Monetization | **Free** | Subscription |
| Size | 22 MB | 204 MB |
| Requires iOS | **9.0** | 16.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 17+ | 17+ |
| Developer | [L'Institut universitaire de cardiologie et de pneumologie de Québec (IUCPQ)](https://appshunter.io/developer/576953454) | [Philippe FURGER](https://appshunter.io/developer/1055742280) |

## What reviewers say

### Guide AOD

[App page](https://appshunter.io/ios/app/guide-aod/id983984632)

This medical reference app provides healthcare professionals with practical information on direct oral anticoagulants. It covers indications, dosages, precautions, interactions, and patient management, including useful calculators for risk assessment and renal clearance.

**Highlights:** Direct oral anticoagulant information, Dosage and renal adjustment, Precautions and contraindications, Bleeding management, Peri/post-operative management, Risk assessment calculators

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

**In-app purchases:** none


### SURF

[App page](https://appshunter.io/ios/app/surf/id1055743301)

Access evidence-based medical content for internal medicine, differential diagnosis, and lab values. This comprehensive guide is designed for residents, general practitioners, and specialists, offering a vast amount of information from multiple expert-authored books.

**Highlights:** Evidence-based medical content, Differential diagnosis of symptoms, Lab value interpretation, Comprehensive internal medicine, Links to external calculators, Accessible on multiple devices

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 year | $99.99 | per year |


## Frequently asked questions

### Is Guide AOD free?

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

### Is SURF free?

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

### Do Guide AOD or SURF have ads?

Neither Guide AOD nor SURF shows ads.

### Which is updated more often, Guide AOD or SURF?

Guide AOD ships an update every 2 months, and SURF every 5 months. Most recently, Guide AOD was updated on September 12, 2026 and SURF on October 9, 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.*