# RotaStone vs Feynman rules

The clearest difference is ads: Feynman rules at none against RotaStone's shown. RotaStone's advantage is iOS requirement (12.0 vs 16.0). On price, 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.

## The numbers

| Metric | RotaStone | Feynman rules |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | — |
| Size | 60 MB | 6 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [radiuthree Co., Ltd](https://appshunter.io/developer/1158448737) | [Sungjun Kim](https://appshunter.io/developer/1602461985) |

## What reviewers say

### RotaStone

[App page](https://appshunter.io/ios/app/rotastone/id1619250280)

**Features:** macOS Compatibility

**In-app purchases:** none


### Feynman rules

[App page](https://appshunter.io/ios/app/feynman-rules/id6478752222)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RotaStone free?

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

### Is Feynman rules free?

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

### Do RotaStone or Feynman rules have ads?

RotaStone shows ads; Feynman rules does not.

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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.*