# Periop Pacemaker vs ShockRef

The clearest difference is in-app purchases: ShockRef at none against Periop Pacemaker's 2. ShockRef also leads on update cadence (every 4 days vs every 2 months). Periop Pacemaker's advantage is iOS requirement (13.0 vs 26.0). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. Periop Pacemaker sells 2 in-app purchases, starting at $2.99 per year. ShockRef asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for Periop Pacemaker against 5.0 for ShockRef. Both are backed by a comparable volume of ratings — 8 and 3 respectively.

Periop Pacemaker ships an update every 2 months, ShockRef every 4 days. The most recent releases landed on September 27, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Periop Pacemaker | ShockRef |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (8 ratings)](https://appshunter.io/ios/app/periop-pacemaker/id6615070538/reviews) | [5.0 (3 ratings)](https://appshunter.io/ios/app/shockref/id6793122630/reviews) |
| Number of ratings | **8** | 3 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 4 days** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 43 MB | 15 MB |
| Requires iOS | **13.0** | 26.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 17+ | 17+ |
| Developer | [Rhythm Management, LLC](https://appshunter.io/developer/1761518402) | [Rishi Kumar](https://appshunter.io/developer/1434016052) |

## What reviewers say

### Periop Pacemaker

[App page](https://appshunter.io/ios/app/periop-pacemaker/id6615070538)

This app provides medical professionals with a decision algorithm for managing surgical patients with implantable defibrillators or pacemakers. It is based on guidelines endorsed by the Heart Rhythm Society and updated annually by an expert committee.

**Highlights:** Decision algorithm for pacemaker/defibrillator management, Endorsed by Heart Rhythm Society, Based on ASA Perioperative Cardiac Implantable Electronic Device Management Aid, Annual expert committee updates, Designed for medical professionals

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PERIOP PACEMAKER ANNUAL FEE | $2.99 | per year |
| Periop Pacemaker | $7.99 | one-time |


### ShockRef

[App page](https://appshunter.io/ios/app/shockref/id6793122630)

A clinical reference for managing shock and hemodynamics, offering insights into bedside physiology, resuscitation, and mechanical circulatory support. It includes practical calculators and drug references for critical care professionals and students.

**Highlights:** Shock phenotyping, Resuscitation workflows, Vasoactive drug references, Mechanical circulatory support troubleshooting, Physiology-based critical care, Practical calculators

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

**In-app purchases:** none


## Frequently asked questions

### Is Periop Pacemaker free?

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

### Is ShockRef free?

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

### Which has better reviews, Periop Pacemaker or ShockRef?

Periop Pacemaker and ShockRef are both rated 5.0 out of 5 on the App Store, from 8 and 3 ratings respectively.

### Do Periop Pacemaker or ShockRef have ads?

Neither Periop Pacemaker nor ShockRef shows ads.

### Which is updated more often, Periop Pacemaker or ShockRef?

Periop Pacemaker ships an update every 2 months, and ShockRef every 4 days. Most recently, Periop Pacemaker was updated on September 27, 2026 and ShockRef on October 10, 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.*