# 室内空气质量管理平台 vs 小牛二维码

The clearest difference is in-app purchases: 室内空气质量管理平台 at none against 小牛二维码's 3. 室内空气质量管理平台 also leads on device support and iOS requirement (9.0 vs 12.0). On price there is nothing between them.

Both are free to download. 小牛二维码 sells 3 in-app purchases, starting at $0.99 per 7 days. 室内空气质量管理平台 asks for nothing beyond the download.

## The numbers

| Metric | 室内空气质量管理平台 | 小牛二维码 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | — |
| Update frequency | Every 3 weeks | — |
| Size | 39 MB | 35 MB |
| Requires iOS | **9.0** | 12.0 |
| Devices | **iPhone, iPod** | — |
| Age rating | 4+ | 4+ |
| Developer | [琦 谈](https://appshunter.io/developer/1599425748) | [Beijing Xiaoniu Kouding Technology Co., Ltd.](https://appshunter.io/developer/1733497912) |

## What reviewers say

### 室内空气质量管理平台

[App page](https://appshunter.io/ios/app/id1599443334)

**Features:** macOS Compatibility

**In-app purchases:** none


### 小牛二维码

[App page](https://appshunter.io/ios/app/id6478612032)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Subscribe Weekly | $0.99 | per 7 days |
| Subscribe Monthly | $0.99 | per month |
| Subscribe Annually | $5.99 | per year |


## Frequently asked questions

### Is 室内空气质量管理平台 free?

室内空气质量管理平台 is free to download, with no in-app purchases.

### Is 小牛二维码 free?

小牛二维码 is free to download, with in-app purchases available.

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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.*