# calcMod vs Prime Not Prime

The clearest difference is rating: calcMod at 5.0 against Prime Not Prime's 4.3. calcMod also leads on iOS requirement (15.0 vs 17.0). Prime Not Prime's advantage is update cadence (monthly vs every 18 months) and ratings volume (6 vs 1). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

calcMod holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: Prime Not Prime has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.

calcMod ships an update every 18 months, Prime Not Prime monthly. The most recent releases landed on October 26, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | calcMod | Prime Not Prime |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/calcmod-light/id1445360983/reviews)** | [4.3 (6 ratings)](https://appshunter.io/ios/app/prime-not-prime/id6738664674/reviews) |
| Number of ratings | 1 | **6** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 18 months | **Monthly** |
| Monetization | Free | Free |
| Size | 1 MB | 15 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Alain Cardinaux](https://appshunter.io/developer/1443066124) | [Richard Witherspoon](https://appshunter.io/developer/1690898003) |

## What reviewers say

### calcMod

[App page](https://appshunter.io/ios/app/calcmod-light/id1445360983)

This application helps users perform complex mathematical calculations, including factorials, primality tests, and modular arithmetic. It's designed for students and educators interested in number theory and the properties of integers.

**Highlights:** Factorial calculation up to 80!, Primality testing with change mod function, Divisor identification, Modular exponentiation, Modular inverse calculation, Number storage and recall

**Features:** macOS Compatibility

**In-app purchases:** none


### Prime Not Prime

[App page](https://appshunter.io/ios/app/prime-not-prime/id6738664674)

A fast-paced game that combines number recognition with a swiping mechanic. Players swipe right for prime numbers and left for non-primes, aiming to build long streaks. It's designed to be both educational and entertaining, with leaderboards for competitive play.

**Highlights:** Addictive swiping gameplay, Test prime number knowledge, Build streaks and complete challenges, Global leaderboards, Vibrant visuals and animations

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is calcMod free?

calcMod is free to download, with no in-app purchases.

### Is Prime Not Prime free?

Prime Not Prime is free to download, with no in-app purchases.

### Which has better reviews, calcMod or Prime Not Prime?

calcMod is rated higher. calcMod averages 5.0 out of 5 from 1 ratings, while Prime Not Prime averages 4.3 from 6 ratings.

### Do calcMod or Prime Not Prime have ads?

Neither calcMod nor Prime Not Prime shows ads.

### Which is updated more often, calcMod or Prime Not Prime?

calcMod ships an update every 18 months, and Prime Not Prime monthly. Most recently, calcMod was updated on October 26, 2026 and Prime Not Prime on October 30, 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.*