# Preop360 vs GasClass

The clearest difference is in-app purchases: GasClass at none against Preop360's 1. GasClass also leads on update cadence (daily vs every 3 months). Preop360's advantage is device support (3 vs 1) and iOS requirement (15.1 vs 17.0). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. Preop360 sells 1 in-app purchase, starting at $4.99 per month. GasClass asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for Preop360 against 5.0 for GasClass. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Preop360 ships an update every 3 months, GasClass daily. The most recent releases landed on November 5, 2026 and November 13, 2026 respectively.

## The numbers

| Metric | Preop360 | GasClass |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (2 ratings)](https://appshunter.io/ios/app/preop360/id6746079405/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/gasclass/id6776366614/reviews) |
| Number of ratings | **2** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Daily** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 40 MB | 8 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 12+ | 17+ |
| Developer | [CARE DECISIONS LLC](https://appshunter.io/developer/1734179704) | [James Germi](https://appshunter.io/developer/6776366616) |

## What reviewers say

### Preop360

[App page](https://appshunter.io/ios/app/preop360/id6746079405)

This app provides evidence-based support for clinicians evaluating adult patients for noncardiac surgery. It incorporates patient comorbidities and medications with interactive calculators to assess perioperative risk. Direct links to references and explanations aid in decision-making and learning.

**Highlights:** Evidence-based preoperative assessment, Interactive risk calculators (RCRI, DASI), Incorporates comorbidities and medications, Links to key references and explanations, Streamlines patient preparation, Standardizes assessments

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basic Plan | $4.99 | per month |


### GasClass

[App page](https://appshunter.io/ios/app/gasclass/id6776366614)

This app offers audio-first lectures and a question bank for anesthesiology board review. It covers a wide range of topics and includes optional on-screen slides for visual learners. Designed for residents, fellows, and practicing professionals.

**Highlights:** Audio-first lectures, Exam-focused content, Comprehensive topic coverage, Board-style question bank, Synced on-screen slides, Designed for trainees

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

**In-app purchases:** none


## Frequently asked questions

### Is Preop360 free?

Preop360 is free to download, with in-app purchases available.

### Is GasClass free?

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

### Which has better reviews, Preop360 or GasClass?

Preop360 and GasClass are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.

### Do Preop360 or GasClass have ads?

Neither Preop360 nor GasClass shows ads.

### Which is updated more often, Preop360 or GasClass?

Preop360 ships an update every 3 months, and GasClass daily. Most recently, Preop360 was updated on November 5, 2026 and GasClass on November 13, 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.*