# Constant Challenge — π & e Challenge — Pi & Euler —

> π & e Challenge — Pi & Euler — (iPhone/iPad app by Kaname Inoue.)

- Source: https://appshunter.io/ios/app/constant-challenge/id6761248442 (this page in markdown: same URL + `.md`)
- Developer: [Kaname Inoue](https://appshunter.io/developer/1888387338)
- Category: Games
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 26.0 · 16 MB
- Languages: American English, Japanese
- Released: 2026-05-19
- Data updated: 2026-07-21
- User reviews in markdown: https://appshunter.io/ios/app/constant-challenge/id6761248442/reviews.md

## What is Constant Challenge?

Constant Challenge is a training app designed to help you memorize mathematical constants like π (pi) and e while testing your skills through various challenge modes.

Each constant offers the same set of game modes, allowing you to practice, compete, and improve your memory and speed.

Features:
- Practice Mode: Learn and memorize digits at your own pace
- Time Attack Mode: Enter as many correct digits as possible within a time limit
- Stage Mode: Progress through structured levels of increasing difficulty
- Local Battle Mode: Competitive play possible

Track your performance, challenge yourself, and aim for high scores.

Perfect for students, math enthusiasts, and anyone who enjoys memory challenges.

Note: This app focuses on memorization and training of mathematical constants.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Unlock the Square Root of 2 (√2) | $0.99 | one-time |
| Unlock the Golden Ratio (φ) | $0.99 | one-time |
| Unlock the Euler–Mascheroni (γ) | $0.99 | one-time |



## Version history (last 3 releases)

### 1.0.2 — 2026-05-21

Fixed a crash issue on macOS．

### 1.0.1 — 2026-05-20

Improved iCloud save synchronization and fixed bugs in Local Battle mode.

### 1.0.0 — 2026-05-19

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-21.*