# Number Line vs Mr Kai

The clearest difference is update cadence: Mr Kai at daily against Number Line's every 15 months. Number Line's advantage is iOS requirement (13.0 vs 16.6). On price, ads, in-app purchases and device support there is nothing between them.

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

Number Line ships an update every 15 months, Mr Kai daily. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Number Line | Mr Kai |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (5 ratings)](https://appshunter.io/ios/app/number-line/id1531893217/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Daily** |
| Monetization | Free | — |
| Size | 16 MB | 172 MB |
| Requires iOS | **13.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [Blastoff Design](https://appshunter.io/developer/1455360972) | [Henry Willis](https://appshunter.io/developer/1857291484) |

## What reviewers say

### Number Line

[App page](https://appshunter.io/ios/app/number-line/id1531893217)

This app provides an interactive number line for educational purposes, enabling users to visualize numbers, perform various math games, and practice rounding. Its simple interface supports zooming, swiping, and marking numbers with pins or freehand drawing.

**Highlights:** Infinite number line visualization, Rounding practice (nearest 10, 100, 10,000), Number comparison, Pinch-to-zoom functionality, Swipe navigation, Search for specific numbers, Pin marking, Freehand drawing tool

**In-app purchases:** none


### Mr Kai

[App page](https://appshunter.io/ios/app/mr-kai/id6759115076)

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

**In-app purchases:** none


## Frequently asked questions

### Is Number Line free?

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

### Is Mr Kai free?

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

### Do Number Line or Mr Kai have ads?

Neither Number Line nor Mr Kai shows ads.

### Which is updated more often, Number Line or Mr Kai?

Number Line ships an update every 15 months, and Mr Kai daily. Most recently, Number Line was updated on October 24, 2026 and Mr Kai on October 25, 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.*