# Probability vs IntroStat

The clearest difference is price: IntroStat at Free against Probability's $1.99. IntroStat also leads on iOS requirement (11.0 vs 14.0). Probability's advantage is in-app purchases (none vs 1) and ads (none vs shown). On rating, review sentiment, update cadence and device support there is nothing between them.

IntroStat is free to download; Probability costs $1.99 up front. IntroStat sells 1 one-off in-app purchase. Probability asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.9 for Probability against 4.9 for IntroStat. That said, the two scores are not equally well evidenced: Probability has 193 ratings behind it against 24, so its average is the more settled of the two. Written reviews are what separate them: 97% of Probability's written reviews are positive against 92% of IntroStat's.

Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on September 23, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | Probability | IntroStat |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | [4.9 (193 ratings)](https://appshunter.io/ios/app/probability-distributions/id889106396/reviews) | **[4.9 (24 ratings)](https://appshunter.io/ios/app/introstat-statistics-solver/id1592602025/reviews)** |
| Number of ratings | **193** | 24 |
| Positive reviews | **97.2% of reviews** | 92.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | Every 3 months |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | **#33** | — |
| Size | 2 MB | 38 MB |
| Requires iOS | 14.0 | **11.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Matthew Bognar](https://appshunter.io/developer/889106399) | [Zhiyi Zhang](https://appshunter.io/developer/1592602327) |

## What reviewers say

### Probability

[App page](https://appshunter.io/ios/app/probability-distributions/id889106396)

**Currently charting:** #33 Top Paid · Education (US App Store)

Calculate probabilities, find percentiles, and visualize probability density or mass functions for a wide range of continuous and discrete statistical distributions. Explore common distributions like normal, binomial, Poisson, and many more.

**Highlights:** Compute probabilities, Determine percentiles, Plot probability density function, Plot probability mass function, Supports 10+ continuous distributions, Supports 5+ discrete distributions

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 👍 Easy to use interface
- 📊 Great for probability distributions
- 💡 Useful for checking work and homework
- 💰 Free advanced functions
- 📈 Visualizes data and distributions

**What reviewers complain about**

- 🚫 Not allowed on some exams
- 🤔 Some users want more features

**Requested features**

- Exam mode similar to Geogebra
- Poisson distribution
- Allow setting plot boundaries (e.g., for Beta distribution)
- Make formulae available in offline mode
- Clearly introduce parameters


### IntroStat

[App page](https://appshunter.io/ios/app/introstat-statistics-solver/id1592602025)

This app serves as a comprehensive statistics calculator and learning tool for introductory statistics courses. It offers a wide range of calculation features, data visualization, and an integrated textbook with formulas and examples.

**Highlights:** Summary statistics calculation, Data visualization (boxplots, histograms), Probability calculations, Hypothesis testing, Confidence intervals, Integrated statistics textbook

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| IntroStat Premium Features | $4.99 | one-time |


## Frequently asked questions

### Is Probability free?

Probability costs $1.99, with no in-app purchases.

### Is IntroStat free?

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

### Which has better reviews, Probability or IntroStat?

IntroStat is rated higher. Probability averages 4.9 out of 5 from 193 ratings, while IntroStat averages 4.9 from 24 ratings.

### Do Probability or IntroStat have ads?

IntroStat shows ads; Probability does not.

### Which is updated more often, Probability or IntroStat?

Probability ships an update every 3 months, and IntroStat every 3 months. Most recently, Probability was updated on September 23, 2026 and IntroStat on September 18, 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.*