# Let's Sum It vs book4kids

The clearest difference is in-app purchases: Let's Sum It at none against book4kids's 2. Let's Sum It also leads on iOS requirement (10.0 vs 17.0). book4kids's advantage is update cadence (every 3 weeks vs every 3 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. Let's Sum It asks for nothing beyond the download.

Let's Sum It ships an update every 3 months, book4kids every 3 weeks. The most recent releases landed on October 9, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Let's Sum It | book4kids |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Size | 37 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

### Let's Sum It

[App page](https://appshunter.io/ios/app/lets-sum-it/id1125545882)

**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 Let's Sum It free?

Let's Sum It is free to download, with no in-app purchases.

### Is book4kids free?

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

### Do Let's Sum It or book4kids have ads?

Neither Let's Sum It nor book4kids shows ads.

### Which is updated more often, Let's Sum It or book4kids?

Let's Sum It ships an update every 3 months, and book4kids every 3 weeks. Most recently, Let's Sum It was updated on October 9, 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.*