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Probability-Distributions

by Matthew Bognar

  • Education
  • Paid
  • Small & simple · 97
View on the App Store
Rating
4.9
193 ratings · US storefront
Top 89%among 90 Education apps
Last update
Oct 11, 2026
Version 6.1
Size
7 MB
Category
Education
Tracked since
Oct 9, 2026

Estimated revenue

A model estimate with a likely range, not a reported figure.

No estimate. Apps outside the grossing charts, and some countries, have no reliable rank-to-revenue curve, so we show nothing rather than a guess.

How this estimate is made

Rank: we take the app's best Top Grossing rank on the latest chart day. Category ranks are converted into an equivalent overall rank, because a #10 in Finance earns far less than a #10 overall.

Curve: that equivalent rank is read off a rank-to-revenue curve anchored on public company revenue and market-data reports for the US iPhone App Store.

Country: the curve is scaled per country (Japan is roughly a third of the US, Türkiye under 1%). Where we have no scale, such as China, there is no estimate.

Range: the likely range widens with country, category and chart depth. It is a plausible span, not a statistical confidence interval.

Not included: ads, payments outside the App Store, and any difference between gross sales and what the developer keeps. Low confidence means indirect data; medium means several independent sources agree.

Full method

Screenshots

As shown on the App Store listing.

About this app

Text from the App Store listing.

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.

What’s new

Release notes for the latest version, as written by the developer.

v6.1

Fix for iOS keyboard issue in certain locales.

Rank history

Daily position in the Argentina charts. #1 is at the top.

Best rank
#1
Current rank
#1
Days charting
7 of 7

On the charts today

Small & simple score

How realistic it is for a small team to build something like this.

97/100

Small & simple

  • Developer size100% · 25

    Developer: 1 app on the charts

  • Audience size100% · 20

    Ratings: 193

  • App size100% · 10

    Size: 7 MB

  • Price model100% · 15

    Price model: paid

  • Demand proof90% · 30

    Best rank #1, 9 countries

An indicator, not a fact. We can't see team size. Calculated Oct 24, 2026 · method i2

How the score works

Version history

  • 6.1LatestReleased Oct 11, 2026
  • 6.0.0Released Oct 6, 2026