# Bayes' post vs ACP MKSAP

The clearest difference is rating: ACP MKSAP at 4.2 against Bayes' post's 3.7. ACP MKSAP also leads on update cadence (every 10 days vs every 23 months) and ratings volume (17 vs 3). Bayes' post's advantage is in-app purchases (none vs 1) and iOS requirement (9.0 vs 13.0). On price, review sentiment, ads and device support there is nothing between them.

Both are free to download. ACP MKSAP sells 1 in-app purchase, starting at $999.99 per year. Bayes' post asks for nothing beyond the download.

ACP MKSAP holds the better App Store score, 4.2 against 3.7. That said, the two scores are not equally well evidenced: ACP MKSAP has 17 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 50% of Bayes' post's written reviews are positive against 57% of ACP MKSAP's.

Bayes' post ships an update every 23 months, ACP MKSAP every 10 days. The most recent releases landed on November 10, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Bayes' post | ACP MKSAP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/bayes-post-test-probability-calculator/id371920137/reviews) | **[4.2 (17 ratings)](https://appshunter.io/ios/app/acp-mksap/id6739636797/reviews)** |
| Number of ratings | 3 | **17** |
| Positive reviews | 50.0% of reviews | **57.1% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 23 months | **Every 10 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 20 MB | 540 MB |
| Requires iOS | **9.0** | 13.0 |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, iPod |
| Age rating | 12+ | 17+ |
| Developer | [Keiji Matsui](https://appshunter.io/developer/365287272) | [American College of Physicians](https://appshunter.io/developer/371090673) |

## What reviewers say

### Bayes' post

[App page](https://appshunter.io/ios/app/bayes-post-test-probability-calculator/id371920137)

This medical app calculates the probability of a disease after a diagnostic test. It uses pre-test probability, test sensitivity, and specificity to determine post-test probabilities for both positive and negative results.

**Highlights:** Calculate post-test probability, Input pre-test probability, Use test sensitivity, Use test specificity, Analyze positive results, Analyze negative results

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### ACP MKSAP

[App page](https://appshunter.io/ios/app/acp-mksap/id6739636797)

Access comprehensive internal medicine knowledge and practice exam-style questions offline. This app syncs your progress with the online version when connected to the internet. It's designed for physicians to stay updated on the latest evidence and enhance their clinical decision-making skills.

**Highlights:** Offline access to text and questions, Thousands of exam-like multiple-choice questions, Patient-based clinical scenarios, Syncs progress with online version, Includes figures, charts, and tables, Targets knowledge gaps

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Non-member in-app price | $999.99 | per year |


## Frequently asked questions

### Is Bayes' post free?

Bayes' post is free to download, with no in-app purchases.

### Is ACP MKSAP free?

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

### Which has better reviews, Bayes' post or ACP MKSAP?

ACP MKSAP is rated higher. Bayes' post averages 3.7 out of 5 from 3 ratings, while ACP MKSAP averages 4.2 from 17 ratings.

### Do Bayes' post or ACP MKSAP have ads?

Neither Bayes' post nor ACP MKSAP shows ads.

### Which is updated more often, Bayes' post or ACP MKSAP?

Bayes' post ships an update every 23 months, and ACP MKSAP every 10 days. Most recently, Bayes' post was updated on November 10, 2026 and ACP MKSAP on November 3, 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.*