# Prime Cracker vs Rectangles & Primes

The clearest difference is device support: Prime Cracker at 5 against Rectangles & Primes's 3. On price, update cadence, 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.

Prime Cracker ships an update every 2 weeks, Rectangles & Primes every 3 weeks. The most recent releases landed on September 25, 2026 and September 15, 2026 respectively.

## The numbers

| Metric | Prime Cracker | Rectangles & Primes |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (31 ratings)](https://appshunter.io/ios/app/prime-cracker/id1281280649/reviews)** | — |
| Number of ratings | **31** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | Free | — |
| Size | 6 MB | 10 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | **iPhone, iPad, iPod, Mac, Apple Watch** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sven Freitag](https://appshunter.io/developer/1281280648) | [Johannes Charra](https://appshunter.io/developer/1557733427) |

## What reviewers say

### Prime Cracker

[App page](https://appshunter.io/ios/app/prime-cracker/id1281280649)

This app helps users explore the fascinating world of prime numbers. It allows you to check if a number is prime, find its factors, and discover nearby primes. You can also analyze ranges of numbers for primes and twin primes.

**Highlights:** Determine primality and factors, Find prime position, Explore nearby primes, Check number ranges for primes, Identify twin primes

**In-app purchases:** none


### Rectangles & Primes

[App page](https://appshunter.io/ios/app/rectangles-and-primes/id1572074176)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Prime Cracker free?

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

### Is Rectangles & Primes free?

Rectangles & Primes is free to download, with no in-app purchases.

### Do Prime Cracker or Rectangles & Primes have ads?

Neither Prime Cracker nor Rectangles & Primes shows ads.

### Which is updated more often, Prime Cracker or Rectangles & Primes?

Prime Cracker ships an update every 2 weeks, and Rectangles & Primes every 3 weeks. Most recently, Prime Cracker was updated on September 25, 2026 and Rectangles & Primes on September 15, 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.*