← Back to charts
Probability-Distributions icon
APP STORE

Probability-Distributions

Matthew Bognar · Education · United States store
NOT IN TOP 100 HERE
View on App Store ↗ Instagram card Google Play version →
Revenue a month, worldwide EST
$385
Likely $128 to $1.2K
▼ 54.7% in 13 days
New ratings
+0
in 1 days, 253 in total
Rating
4.9 of 5
193 ratings in this store
Countries it ranks in
0
was 0 on Oct 18, 2026

Revenue

Estimated from the grossing charts of Oct 24, 2026 in the 53 countries we track, and ratings growth on the App Store.

EST. REVENUE / YEAR · WORLDWIDE
$4.6K
1.7 new ratings a month on average since launch
EST. LIFETIME DOWNLOADS
6.8K to 19.3K
Estimated from ratings count
WHERE ITS USERS ARE · SHARE OF RATINGS
  • United States 193 ratings88%
  • Brazil 6 ratings3%
  • United Kingdom 4 ratings2%
  • France 4 ratings2%
  • Spain 4 ratings2%
  • Italy 4 ratings2%
  • South Korea 2 ratings1%
  • Netherlands 1 ratings0%
HOW SURE ARE WE
Not in any grossing chart, so this comes from ratings growth (1.7 new ratings a month on average since launch): revenue grows with new ratings, more slowly for apps that collect ratings fast. Tested on 418 apps with verified revenue: typically off by about 2 times, and big earners tend to come out low. Countries we don't track (and Google Play in China, which doesn't exist) aren't included, and neither are ads or web payments. Gross revenue before store fees.
RATINGS
193
AVG RATING
4.90
PRICE
$1.99
AGE
12.4y
LAST UPDATE
13d ago
VERSION
6.1
SIZE
7 MB
AGE RATING
17+

Last 30 days

From our daily snapshots of every grossing chart and daily ratings counts.

DAYS IN A GROSSING CHART
2 / 30
COUNTRIES NOW
0 (was 0)
NEW RATINGS, LAST 1 DAYS
+0
EST. REVENUE A MONTH, DAILY · BOTH STORES EST
Show daily values
Sep 26, 2026not in a grossing chart
Sep 27, 2026not in a grossing chart
Sep 28, 2026not in a grossing chart
Sep 29, 2026not in a grossing chart
Sep 30, 2026not in a grossing chart
Oct 1, 2026not in a grossing chart
Oct 2, 2026not in a grossing chart
Oct 3, 2026not in a grossing chart
Oct 4, 2026not in a grossing chart
Oct 5, 2026not in a grossing chart
Oct 6, 2026not in a grossing chart
Oct 7, 2026not in a grossing chart
Oct 8, 2026not in a grossing chart
Oct 9, 2026not in a grossing chart
Oct 10, 2026$3.3K a month
Oct 11, 2026not in a grossing chart
Oct 12, 2026not in a grossing chart
Oct 13, 2026not in a grossing chart
Oct 14, 2026not in a grossing chart
Oct 15, 2026not in a grossing chart
Oct 16, 2026not in a grossing chart
Oct 17, 2026not in a grossing chart
Oct 18, 2026not in a grossing chart
Oct 19, 2026not in a grossing chart
Oct 20, 2026not in a grossing chart
Oct 21, 2026not in a grossing chart
Oct 22, 2026not in a grossing chart
Oct 23, 2026$1.5K a month
Oct 24, 2026not in a grossing chart
Oct 25, 2026not in a grossing chart
The same estimate as the headline, saved every day. Best rank Sep 26, 2026: not ranked. Now: not ranked.
RATINGS IN THE CORE COUNTRIES, DAILY
Show daily values
Oct 23, 2026253 ratings
Oct 24, 2026253 ratings
253 on Oct 23, 2026, 253 on Oct 24, 2026. New ratings track new downloads, even outside the charts.

Money and momentum

Measured from the store, not estimated.

WHAT IT CHARGES
No in-app purchases
Earns from its upfront price, ads or payments outside the store.
REVIEW MOMENTUM
0.1 reviews / week
  • Trendfalling
  • Recent reviews average5.0 stars
  • Recent 1 and 2 star share0%
From the latest 79 written reviews, covering 4509 days.
RELEASE CADENCE
2 updates in 90 days
  • Typical gap between releases87 days
From the last 19 versions listed on the App Store.
RATING BREAKDOWN
193 ratings
5★97%
4★0%
3★1%
2★0%
1★2%

What users want

From the latest 79 reviews on the United States App Store, Jun 21, 2014 to Nov 12, 2025: 0% are 1 or 2 stars. Open a theme to read what people wrote.

WHAT THEY COMPLAIN ABOUT · SHARE OF BAD REVIEWS

Only 0 of the latest 79 reviews are 1 or 2 stars, too few to find patterns. Users are mostly happy.

WHAT THEY ASK FOR
  • (Future feature request, if you have time: Allow setting plot boundaries. 5★, Dec 12, 2018
  • It would help to add a couple of usability things. 5★, Jun 21, 2014
  • More importantly, it would be great to add some options after the graph is rendered. 5★, Jun 21, 2014
WORDS THAT KEEP COMING UP IN BAD REVIEWS

Nothing stands out.

WHAT THEY LOVE · SHARE OF GOOD REVIEWS
Easy to use18%

14 of the 4 and 5 star reviews.

★★★★★ Subject line says it all. P(Z<x) for normal and a bunch more for essential statistical tests. THANK YOU!!!!
★★★★★ It makes it easy to calculate probabilities using any distribution that I have needed.
★★★★★ This app is super helpful and easy to use!
Useful, it helps17%

13 of the 4 and 5 star reviews.

★★★★★ This could be really useful for students in college stats courses who are on a budget and can't afford to buy a $100+ dollar graphing calculator.
★★★★★ Web app on hypothesis testing and confidence interval is even more useful, especially the version where raw data can be the input!!
★★★★★ This app is super helpful and easy to use!
Fast5%

4 of the 4 and 5 star reviews.

★★★★★ It's a great tool for quick statistics and so many people in my company are using it.
★★★★★ A smooth and well polished app that is extremely user friendly.
★★★★★ Great for quick answers to probability questions, particularly for school.
Looks great3%

2 of the 4 and 5 star reviews.

★★★★★ Very easy to use, nice user interface.
★★★★★ This app is excellent from a UI perspective.
Accurate, great results3%

2 of the 4 and 5 star reviews.

Found by matching words and phrases in the reviews, not read by a person. A review can count toward more than one theme.

What users say

Latest reviews, United States App Store.

★★★★★Nov 12, 2025
Good for education but needs improvement

As a teacher I need exam mode such as Geogebra to use during exams

★★★★★Mar 31, 2024
Finally! A simple, free N(0, 1) calculator.

Subject line says it all. P(Z<x) for normal and a bunch more for essential statistical tests. THANK YOU!!!!

★★★★★Oct 4, 2021
Sick App

I love probability distributions.

★★★★★Nov 13, 2020
iPhone SE (2020) issue has been fixed

Works perfectly now. Much better than using tables.

★★★★★Feb 12, 2020
BOGNAR IS THE GOAT

Goat status: 100%

★★★★★Nov 19, 2019
Does advanced functions for free!

This could be really useful for students in college stats courses who are on a budget and can’t afford to buy a $100+ dollar graphing calculator. It does basic advanced functions like binomial pdf - for free. I don’t know if it does invNorm or Z-Test calculations ( possibly not) but for a calculation app that you don’t have to pay for this is pretty great and was just what I was looking for.

Apps like this

Same category, earning about as much.

BrightLearn Portal$386 a month ESTLanguoso: AI Language Tutor$390 a month ESTNawa: Learn Arabic$377 a month ESTBaian: Khutbah Translator$401 a month ESTТест в прокуратуру$401 a month ESTJAMB CBT + WAEC Past Questions$368 a month ESTAmenzi Ordine Publica$368 a month ESTElectrician Pro$404 a month EST

Store screenshots

ScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshotScreenshot

App Store ads

Apple Search Ads this app ran in the last 90 days, from Apple's public ad repository.

No App Store ads in the EU
None in the last 90 days.

Apple only publishes ads shown in the EU (EU Digital Services Act), with a 7 day delay. An app that advertises only outside the EU shows nothing here.

Growth research

Where this app is buying and earning its users. Each link opens pre filtered.

Meta Ad Library ↗Active Facebook and Instagram adsTikTok Creative Center ↗Top performing TikTok adsTikTok creators ↗Organic videos mentioning the appInstagram ↗Reels and posts under its hashtagYouTube ↗Reviews, tutorials and ShortsDeveloper site ↗Landing page and pricing

ASO keywords

Most repeated terms in the listing. Highlighted ones also appear in the title.

normal2binomial2versions2

What's new in 6.1

Fix for iOS keyboard issue in certain locales.

Released Jun 22, 2014. Current version shipped Oct 11, 2026.

Store description

Replace your statistical tables with an interactive, graphical app! Compute probabilities & percentiles, and plot the probability density/mass function for the normal (Gaussian), t, chi-square, F, exponential, gamma, beta, log-normal, and Uniform, binomial, geometric (2 versions), hypergeometric, Poisson, and negative binomial (2 versions) distributions. Now supports Español.

See this store page in another country

Prices, ranks and reviews are per country. Revenue above is already worldwide.

United KingdomGermanyJapanBrazilIndia