# Math King vs eReadBook

The clearest difference is in-app purchases: eReadBook at none against Math King's 1. eReadBook also leads on iOS requirement (10.0 vs 15.0). Math King's advantage is update cadence (every 2 months vs every 10 months). On price, ads and device support there is nothing between them.

Both are free to download. Math King sells 1 one-off in-app purchase. eReadBook asks for nothing beyond the download.

Math King ships an update every 2 months, eReadBook every 10 months. The most recent releases landed on April 26, 2026 and September 15, 2026 respectively.

## The numbers

| Metric | Math King | eReadBook |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 10 months |
| Size | 69 MB | 1.5 GB |
| Requires iOS | 15.0 | **10.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sadgun Infotech](https://appshunter.io/developer/1563703272) | [Guangzhou Childhood Technology Co.,Ltd](https://appshunter.io/developer/375730659) |

## What reviewers say

### Math King

[App page](https://appshunter.io/ios/app/math-king/id1617597133)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $1.99 | one-time |


### eReadBook

[App page](https://appshunter.io/ios/app/ereadbook/id6443910427)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Math King free?

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

### Is eReadBook free?

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

### Do Math King or eReadBook have ads?

Neither Math King nor eReadBook shows ads.

### Which is updated more often, Math King or eReadBook?

Math King ships an update every 2 months, and eReadBook every 10 months. Most recently, Math King was updated on April 26, 2026 and eReadBook on September 15, 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.*