# N'Back Fan vs CheckPrimeNumbers

The clearest difference is price: N'Back Fan at Free against CheckPrimeNumbers's $0.99. CheckPrimeNumbers's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

N'Back Fan is free to download; CheckPrimeNumbers costs $0.99 up front. N'Back Fan sells 1 one-off in-app purchase. CheckPrimeNumbers asks for nothing beyond the download.

## The numbers

| Metric | N'Back Fan | CheckPrimeNumbers |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 9 months | — |
| Size | 7 MB | 0 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) | [Sreekanth Parigela](https://appshunter.io/developer/1763791561) |

## What reviewers say

### N'Back Fan

[App page](https://appshunter.io/ios/app/nback-fan/id6449070102)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| remove ads and extend to 12 | $1.99 | one-time |


### CheckPrimeNumbers

[App page](https://appshunter.io/ios/app/checkprimenumbers/id6670205769)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is N'Back Fan free?

N'Back Fan is free to download, with in-app purchases available.

### Is CheckPrimeNumbers free?

CheckPrimeNumbers costs $0.99, with no in-app purchases.

### Do N'Back Fan or CheckPrimeNumbers have ads?

N'Back Fan shows ads; CheckPrimeNumbers does not.

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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.*