# M4D vs USim OS

The clearest difference is device support: USim OS at 2 against M4D's —. On price, in-app purchases and iOS requirement 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 | M4D | USim OS |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | — | No |
| Update frequency | — | Weekly |
| Size | 37 MB | 77 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | — | **iPhone, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Teoh Ge Liang](https://appshunter.io/developer/1697827247) | [Ruiyu Chen](https://appshunter.io/developer/1762343435) |

## What reviewers say

### M4D

[App page](https://appshunter.io/ios/app/m4d/id6451379122)

**In-app purchases:** none


### USim OS

[App page](https://appshunter.io/ios/app/usim-os/id6740407423)

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

**In-app purchases:** none


## Frequently asked questions

### Is M4D free?

M4D is free to download, with no in-app purchases.

### Is USim OS free?

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

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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.*