# 预检验机 vs 紫鸾

The clearest difference is update cadence: 预检验机 at every 10 days against 紫鸾's monthly. 预检验机 also leads on iOS requirement (8.0 vs 13.0). On price, ads, 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.

预检验机 ships an update every 10 days, 紫鸾 monthly. The most recent releases landed on October 9, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | 预检验机 | 紫鸾 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 10 days** | Monthly |
| Size | 7 MB | 196 MB |
| Requires iOS | **8.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Hang Zhou XiangShang Electronic Commerce Co., LTD](https://appshunter.io/developer/938563429) | [TSINGHUA UNIUDC CO.,LTD.](https://appshunter.io/developer/1390965092) |

## What reviewers say

### 预检验机

[App page](https://appshunter.io/ios/app/id1662737388)

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

**In-app purchases:** none


### 紫鸾

[App page](https://appshunter.io/ios/app/id6467690309)

**In-app purchases:** none


## Frequently asked questions

### Is 预检验机 free?

预检验机 is free to download, with no in-app purchases.

### Is 紫鸾 free?

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

### Do 预检验机 or 紫鸾 have ads?

Neither 预检验机 nor 紫鸾 shows ads.

### Which is updated more often, 预检验机 or 紫鸾?

预检验机 ships an update every 10 days, and 紫鸾 monthly. Most recently, 预检验机 was updated on October 9, 2026 and 紫鸾 on October 8, 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.*