# Bayes' post vs Contraception

The clearest difference is rating: Contraception at 4.3 against Bayes' post's 3.7. Contraception also leads on update cadence (every 7 months vs every 23 months) and review sentiment (64% vs 50%). Bayes' post's advantage is iOS requirement (9.0 vs 16.0). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Contraception holds the better App Store score, 4.3 against 3.7. That said, the two scores are not equally well evidenced: Contraception has 27 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 64% of Contraception's.

Bayes' post ships an update every 23 months, Contraception every 7 months. The most recent releases landed on October 2, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Bayes' post | Contraception |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/bayes-post-test-probability-calculator/id371920137/reviews) | **[4.3 (27 ratings)](https://appshunter.io/ios/app/contraception/id595752188/reviews)** |
| Number of ratings | 3 | **27** |
| Positive reviews | 50.0% of reviews | **63.6% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 23 months | **Every 7 months** |
| Monetization | Free | Free |
| Size | 20 MB | 56 MB |
| Requires iOS | **9.0** | 16.0 |
| Devices | **iPhone, iPod, Apple Watch** | iPhone, iPad |
| Age rating | 12+ | 12+ |
| Developer | [Keiji Matsui](https://appshunter.io/developer/365287272) | [Centers For Disease Control and Prevention](https://appshunter.io/developer/439259253) |

## 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

**In-app purchases:** none


### Contraception

[App page](https://appshunter.io/ios/app/contraception/id595752188)

This app provides comprehensive guidelines on contraceptive method use based on medical eligibility criteria and selected practice recommendations. It assists healthcare providers in counseling individuals and couples on family planning choices, covering over 60 medical conditions and numerous clinical situations.

**Highlights:** U.S. Medical Eligibility Criteria (MEC), U.S. Selected Practice Recommendations (SPR), Covers over 60 characteristics/conditions, Addresses numerous clinical situations, Aids healthcare provider counseling, Based on CDC Morbidity and Mortality Weekly Report

**In-app purchases:** none


## Frequently asked questions

### Is Bayes' post free?

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

### Is Contraception free?

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

### Which has better reviews, Bayes' post or Contraception?

Contraception is rated higher. Bayes' post averages 3.7 out of 5 from 3 ratings, while Contraception averages 4.3 from 27 ratings.

### Do Bayes' post or Contraception have ads?

Neither Bayes' post nor Contraception shows ads.

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

Bayes' post ships an update every 23 months, and Contraception every 7 months. Most recently, Bayes' post was updated on October 2, 2026 and Contraception on October 17, 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.*