# Natural Number Kid vs Pi Sequence

The clearest difference is in-app purchases: Natural Number Kid at none against Pi Sequence's 1. Natural Number Kid also leads on update cadence (every 5 days vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Pi Sequence sells 1 one-off in-app purchase. Natural Number Kid asks for nothing beyond the download.

Natural Number Kid ships an update every 5 days, Pi Sequence every 3 months. The most recent releases landed on October 5, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Natural Number Kid | Pi Sequence |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 3 months |
| Size | 2 MB | 29 MB |
| Requires iOS | 18.2 | **17.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Alterscope Solutions LLC](https://appshunter.io/developer/1551052588) | [晓灵 潘](https://appshunter.io/developer/6781908128) |

## What reviewers say

### Natural Number Kid

[App page](https://appshunter.io/ios/app/natural-number-kid/id6741135338)

**Features:** macOS Compatibility

**In-app purchases:** none


### Pi Sequence

[App page](https://appshunter.io/ios/app/pi-sequence-memorize-pi/id6783736734)

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | $3.99 | one-time |


## Frequently asked questions

### Is Natural Number Kid free?

Natural Number Kid is free to download, with no in-app purchases.

### Is Pi Sequence free?

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

### Do Natural Number Kid or Pi Sequence have ads?

Neither Natural Number Kid nor Pi Sequence shows ads.

### Which is updated more often, Natural Number Kid or Pi Sequence?

Natural Number Kid ships an update every 5 days, and Pi Sequence every 3 months. Most recently, Natural Number Kid was updated on October 5, 2026 and Pi Sequence on October 10, 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.*