# Subitize This! vs book4kids

The clearest difference is in-app purchases: Subitize This! at none against book4kids's 2. Subitize This! also leads on iOS requirement (10.0 vs 17.0). book4kids's advantage is update cadence (every 3 weeks vs every 7 months). On price, ads and device support there is nothing between them.

Both are free to download. book4kids sells 2 in-app purchases, starting at $0.49 per month. Subitize This! asks for nothing beyond the download.

Subitize This! ships an update every 7 months, book4kids every 3 weeks. The most recent releases landed on October 24, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Subitize This! | book4kids |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/subitize-this/id1125721532/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 3 weeks** |
| Monetization | Free | — |
| Size | 36 MB | 20 MB |
| Requires iOS | **10.0** | 17.0 |
| Devices | iPad | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Classroom Focused Software](https://appshunter.io/developer/406741679) | [Benjamin TATI](https://appshunter.io/developer/1583386758) |

## What reviewers say

### Subitize This!

[App page](https://appshunter.io/ios/app/subitize-this/id1125721532)

This app helps young children aged 4-7 develop their subitizing skills by practicing recognizing quantities from 1 to 5. It offers options for showing patterns in sets of 4, 6, or 8, with a timer and feedback for responses.

**Highlights:** Subitizing practice 1-5 elements, Options for sets of 4, 6, or 8, Includes a timer, Provides feedback on responses, Designed for ages 4-7

**Features:** macOS Compatibility

**In-app purchases:** none


### book4kids

[App page](https://appshunter.io/ios/app/book4kids/id1587601959)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Book4kids monthly subscription | $0.49 | per month |
| Book4kids annual subscription | $1.00 | per year |


## Frequently asked questions

### Is Subitize This! free?

Subitize This! is free to download, with no in-app purchases.

### Is book4kids free?

book4kids is free to download, with in-app purchases available.

### Do Subitize This! or book4kids have ads?

Neither Subitize This! nor book4kids shows ads.

### Which is updated more often, Subitize This! or book4kids?

Subitize This! ships an update every 7 months, and book4kids every 3 weeks. Most recently, Subitize This! was updated on October 24, 2026 and book4kids on October 17, 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.*