# Udan HESS vs 亿艾斯OA

The clearest difference is update cadence: 亿艾斯OA at every 3 days against Udan HESS's every 3 months. Udan HESS's advantage is iOS requirement (13.0 vs 15.6). 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.

Udan HESS ships an update every 3 months, 亿艾斯OA every 3 days. The most recent releases landed on October 13, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Udan HESS | 亿艾斯OA |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 days** |
| Size | 33 MB | 17 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Anhui Udan Technology Co., Ltd.](https://appshunter.io/developer/1593792520) | [无锡亿艾斯新能源技术有限公司](https://appshunter.io/developer/1762339127) |

## What reviewers say

### Udan HESS

[App page](https://appshunter.io/ios/app/udan-hess/id6443758347)

**Features:** macOS Compatibility

**In-app purchases:** none


### 亿艾斯OA

[App page](https://appshunter.io/ios/app/oa/id6762732678)

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

**In-app purchases:** none


## Frequently asked questions

### Is Udan HESS free?

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

### Is 亿艾斯OA free?

亿艾斯OA is free to download, with no in-app purchases.

### Do Udan HESS or 亿艾斯OA have ads?

Neither Udan HESS nor 亿艾斯OA shows ads.

### Which is updated more often, Udan HESS or 亿艾斯OA?

Udan HESS ships an update every 3 months, and 亿艾斯OA every 3 days. Most recently, Udan HESS was updated on October 13, 2026 and 亿艾斯OA on September 20, 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.*