# Probability vs 百信吧

The clearest difference is in-app purchases: 百信吧 at none against Probability's 1. 百信吧 also leads on update cadence (every 5 days vs every 10 days). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Probability sells 1 one-off in-app purchase. 百信吧 asks for nothing beyond the download.

Probability ships an update every 10 days, 百信吧 every 5 days. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Probability | 百信吧 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/probability-easy-and-practical/id1625073969/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 10 days | **Every 5 days** |
| Monetization | Free with in-app purchases | — |
| Size | 166 MB | 70 MB |
| Requires iOS | 14.0 | **13.0** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Man Hung Sun](https://appshunter.io/developer/1471605573) | [君强 丁](https://appshunter.io/developer/1812944121) |

## What reviewers say

### Probability

[App page](https://appshunter.io/ios/app/probability-easy-and-practical/id1625073969)

Enhance your decision-making skills by learning to assess probabilities with this app. It offers formulas for problem-solving, note-taking capabilities, and interactive tools like dice and coin tosses for practical learning.

**Highlights:** Probability assessment, Decision-making improvement, Problem-solving formulas, Personalized notes, Dice and coin toss simulations

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade | $0.99 | one-time |


### 百信吧

[App page](https://appshunter.io/ios/app/id6745599585)

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

**In-app purchases:** none


## Frequently asked questions

### Is Probability free?

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

### Is 百信吧 free?

百信吧 is free to download, with no in-app purchases.

### Do Probability or 百信吧 have ads?

Neither Probability nor 百信吧 shows ads.

### Which is updated more often, Probability or 百信吧?

Probability ships an update every 10 days, and 百信吧 every 5 days. Most recently, Probability was updated on November 3, 2026 and 百信吧 on October 30, 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.*