# ProbabilityPlayer vs Derivon

The clearest difference is review sentiment: ProbabilityPlayer at 100% against Derivon's 0%. ProbabilityPlayer also leads on ads (none vs shown) and iOS requirement (18.0 vs 26.0). Derivon's advantage is update cadence (every 2 days vs monthly). On price, in-app purchases, monetization model and device support there is nothing between them.

Both are free to download. ProbabilityPlayer sells 1 one-off in-app purchase and Derivon sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

ProbabilityPlayer ships an update monthly, Derivon every 2 days. The most recent releases landed on September 27, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | ProbabilityPlayer | Derivon |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[3.0 (1 ratings)](https://appshunter.io/ios/app/derivon-calculus-practice/id6761150220/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Every 2 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 9 MB | 130 MB |
| Requires iOS | **18.0** | 26.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Motonari Hibi](https://appshunter.io/developer/386737172) | [RYOMA MIZUTANI](https://appshunter.io/developer/1736955493) |

## What reviewers say

### ProbabilityPlayer

[App page](https://appshunter.io/ios/app/probabilityplayer/id6737689746)

Practice probability problems for the Kyotsu Test, a common Japanese university entrance exam. This app focuses on mathematical probability questions and includes diagrams to aid understanding. It is designed to help students prepare for this specific academic assessment.

**Highlights:** Probability problem practice, Kyotsu Test focus, Mathematical probability, Diagrams included, University entrance exam prep

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $1.99 | one-time |


### Derivon

[App page](https://appshunter.io/ios/app/derivon-calculus-practice/id6761150220)

Master calculus concepts like derivatives and integrals through daily, intuitive practice. Earn rewards, collect planets, and build streaks as you progress through challenges. Designed for quick, effective learning sessions.

**Highlights:** Daily calculus problem practice, Earn Star Sand rewards, Collect planets in Gallery, Build and maintain daily streaks, Rank-Up Challenges, Shooting mode for breaks

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 5 Star Fragments | $0.99 | one-time |
| 12 Star Fragments | $1.99 | one-time |
| 32 Star Fragments | $3.99 | one-time |


## Frequently asked questions

### Is ProbabilityPlayer free?

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

### Is Derivon free?

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

### Do ProbabilityPlayer or Derivon have ads?

Derivon shows ads; ProbabilityPlayer does not.

### Which is updated more often, ProbabilityPlayer or Derivon?

ProbabilityPlayer ships an update monthly, and Derivon every 2 days. Most recently, ProbabilityPlayer was updated on September 27, 2026 and Derivon on September 19, 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.*