# Probability Distribution vs iMSSpiece

The clearest difference is in-app purchases: iMSSpiece at none against Probability Distribution's 1. iMSSpiece also leads on rating (5.0 vs 4.5) and update cadence (every 3 days vs every 2 weeks). Probability Distribution's advantage is ratings volume (17 vs 1). On price, ads and iOS requirement there is nothing between them.

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

iMSSpiece holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Probability Distribution has 17 ratings behind it against 1, so its average is the more settled of the two.

Probability Distribution ships an update every 2 weeks, iMSSpiece every 3 days. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Probability Distribution | iMSSpiece |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (17 ratings)](https://appshunter.io/ios/app/probability-distribution/id6447695305/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/imsspiece/id6504674347/reviews)** |
| Number of ratings | **17** | 1 |
| Positive reviews | 33.3% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 3 days** |
| Monetization | Paid | **Free** |
| Size | 7 MB | 321 MB |
| Requires iOS | 16.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Madiyar Aitbayev](https://appshunter.io/developer/1229466587) | [Lisilog](https://appshunter.io/developer/1469355024) |

## What reviewers say

### Probability Distribution

[App page](https://appshunter.io/ios/app/probability-distribution/id6447695305)

This app allows users to calculate probabilities and visualize various continuous and discrete probability distributions. It supports a wide range of common distributions and plans to add more in the future.

**Highlights:** Calculate probabilities, Visualize distributions, Normal (Gaussian) distribution, Binomial distribution, Poisson distribution, Exponential distribution

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All Distributions | $2.99 | one-time |


### iMSSpiece

[App page](https://appshunter.io/ios/app/imsspiece/id6504674347)

This app allows users to experiment with interactive motion sound systems and instrumental scenegraphy. It features a comprehensive score system, an intuitive cue management interface, and a flexible preset system for sound customization. Users can also define and edit regions for motion detection.

**Highlights:** Interactive motion sound systems, Instrumental scenegraphy, Mask Motion with OpenCV, Customizable score system, Intuitive cue management, Faust Soundplayer editor, Editable region system

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

**In-app purchases:** none


## Frequently asked questions

### Is Probability Distribution free?

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

### Is iMSSpiece free?

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

### Which has better reviews, Probability Distribution or iMSSpiece?

iMSSpiece is rated higher. Probability Distribution averages 4.5 out of 5 from 17 ratings, while iMSSpiece averages 5.0 from 1 ratings.

### Do Probability Distribution or iMSSpiece have ads?

Neither Probability Distribution nor iMSSpiece shows ads.

### Which is updated more often, Probability Distribution or iMSSpiece?

Probability Distribution ships an update every 2 weeks, and iMSSpiece every 3 days. Most recently, Probability Distribution was updated on November 3, 2026 and iMSSpiece 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.*