# RezClock vs Master Anesthesia

The clearest difference is review sentiment: Master Anesthesia at 79% against RezClock's 0%. Master Anesthesia also leads on rating (4.9 vs 2.3) and update cadence (every 6 days vs every 35 months). RezClock's advantage is iOS requirement (10.0 vs 15.1). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. RezClock sells 1 in-app purchase, starting at $0.99 per month and Master Anesthesia sells 7 in-app purchases, starting at $69.99 per year. Whichever you choose, the download price is not the number that matters.

Master Anesthesia holds the better App Store score, 4.9 against 2.3. That said, the two scores are not equally well evidenced: Master Anesthesia has 2K ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 0% of RezClock's written reviews are positive against 79% of Master Anesthesia's.

RezClock ships an update every 35 months, Master Anesthesia every 6 days. The most recent releases landed on June 11, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | RezClock | Master Anesthesia |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.3 (3 ratings)](https://appshunter.io/ios/app/rezclock/id988755622/reviews) | **[4.9 (2K ratings)](https://appshunter.io/ios/app/master-anesthesia/id1550793078/reviews)** |
| Number of ratings | 3 | **2K** |
| Positive reviews | 0.0% of reviews | **79.1% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 35 months | **Every 6 days** |
| Monetization | Subscription | Subscription |
| Best chart rank | — | **#120** |
| Size | 24 MB | 69 MB |
| Requires iOS | **10.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Mitra U.S. Computer Solutions, Inc](https://appshunter.io/developer/988434177) | [Matthew Willis](https://appshunter.io/developer/1550793080) |

## What reviewers say

### RezClock

[App page](https://appshunter.io/ios/app/rezclock/id988755622)

Automates medical resident duty hour tracking using location services to log arrival and departure times at clinical sites. Hours can be uploaded to other systems for generating ACGME required reports. Offers a free trial period before subscription.

**Highlights:** Automated time tracking, Location-based geofencing, Duty hours reporting, Data upload to MedProSuite, Free trial period

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RezClock Monthly - $0.99/month | $0.99 | per month |


### Master Anesthesia

[App page](https://appshunter.io/ios/app/master-anesthesia/id1550793078)

**Currently charting:** #120 Top Grossing · Medical (US App Store)

This app provides anesthesia professionals with quick answers to common questions. It highlights anesthetic implications of diseases, surgical cases, and drugs, and includes a searchable acronym list and a comprehensive calculator for dosages, blood loss, and fluid management.

**Highlights:** Disease anesthetic implications, Surgical case anesthetic implications, Drug anesthetic implications, Searchable acronym list, Local anesthetic dosage calculator, Blood volume and loss calculator, Fluid and equipment calculations

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

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Master Anesthesia Contributor | $69.99 | per year |
| Full Access CE | $449.00 | per year |
| Module Unlock | $24.99 | one-time |
| Course Unlock | $99.00 | one-time |
| Master Anesthesia One Time | $99.99 | one-time |
| One-Time | $149.99 | one-time |
| Course Unlock | $449.00 | one-time |

**What reviewers like**

- 👍 Intuitive and user-friendly interface
- 🚀 Efficient and fast calculators
- 📚 Comprehensive information and resources
- 💡 Helpful for clinical practice and preparation
- 🔍 Useful reference for anesthesia providers

**What reviewers complain about**

- 🐛 Frequent crashes and freezes in the calculations section
- 🔒 Issues with purchase verification and login
- 💰 Concerns about the transition to a paid subscription model
- 🔋 High battery consumption and performance issues on older devices

**Reported bugs**

- Incorrect terminology and credentials on the starting screen
- Inconsistent behavior when accessing content after subscription changes

**Requested features**

- Offline access to content
- Apple Watch integration for the calculator
- More detailed and up-to-date information on procedures and conditions


## Frequently asked questions

### Is RezClock free?

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

### Is Master Anesthesia free?

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

### Which has better reviews, RezClock or Master Anesthesia?

Master Anesthesia is rated higher. RezClock averages 2.3 out of 5 from 3 ratings, while Master Anesthesia averages 4.9 from 2K ratings.

### Do RezClock or Master Anesthesia have ads?

Neither RezClock nor Master Anesthesia shows ads.

### Which is updated more often, RezClock or Master Anesthesia?

RezClock ships an update every 35 months, and Master Anesthesia every 6 days. Most recently, RezClock was updated on June 11, 2026 and Master Anesthesia on September 25, 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.*