Comparison

Bayes' post vs ACP MKSAP

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Bayes' post

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
Read full description

Bayes’ post-test probability calculator, an iPhone / iPod touch application, calculates the post-test probability of diseases from pre-test probability and sensitivity of the test and specificity of the test. positive result: post-test probability for positive result negative result: post-test probability for negative result

About

ACP MKSAP

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
Read full description

This app supplements the online version and is included with your ACP MKSAP subscription. Simply log in with your ACP or ACP MKSAP username and password. If you need assistance setting up your account, visit ACP Online. Some functionality within the app requires an active Internet connection. Your suggestions for future updates and enhanced features are welcome at mksap_editors@acponline.org. The new ACP Medical Knowledge Self-Assessment Program℠ (ACP MKSAP℠) provides you with the most current and critical information in the core of internal medicine and its subspecialties so you can stay aware of what you need to know as a practicing physician in internal medicine today. ACP MKSAP consists of well-researched text sections and thousands of exam-like multiple-choice questions along with hundreds of figures, charts, and tables to enhance your learning experience. ACP MKSAP's original, high-quality questions comprise patient-based clinical scenarios based on the latest evidence. Each question will challenge your decision-making, help you discover areas of strength, and target areas for you to update or acquire new knowledge. This app enables ACP MKSAP subscribers to read all of the text and answer all of the questions offline. When you are connected to the Internet, answers will sync automatically with the online version. The publisher of this app, the American College of Physicians, is the largest medical specialty organization in the United States with members in more than 145 countries worldwide. ACP membership includes 161,000 internal medicine physicians (internists), related subspecialists, and medical students. Internal medicine physicians are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness. Subscriber License Agreement: https://mksap.acponline.org/license

Screenshots

Bayes' post1 screens
ACP MKSAP1 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard6 real differences · 4 level
Bayes' post versus ACP MKSAP: the parameters behind the verdict, then further details
ParameterBayes' postACP MKSAP
PriceFreeFree
Rating3.7 (3 ratings)4.2 (17 ratings) — better
Positive reviews50.0% of reviews57.1% of reviews — better
Number of ratings317 — better
Update frequencyEvery 23 monthsEvery 10 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPod, Apple WatchiPhone, iPad, iPod
Requires iOS9.0 — better13.0
Further details — not scored
Size20 MB540 MB
Age rating12+17+
DeveloperKeiji MatsuiAmerican College of Physicians

Customer experience

Bayes' post

All ratings3 ratings
Positive66.7%
Neutral0.0%
Negative33.3%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

ACP MKSAP

All ratings16 ratings
Positive81.3%
Neutral0.0%
Negative18.8%
Written reviews7 reviews
Positive57.1%
Neutral0.0%
Negative42.9%

In-app purchases

None

Bayes' post

No in-app purchases

1 purchases

ACP MKSAP

Subscriptions1
  • Non-member in-app price$999.991 Year

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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