# 掌上购电 vs USB扩展屏

The clearest difference is in-app purchases: 掌上购电 at none against USB扩展屏's 1. 掌上购电 also leads on iOS requirement (9.0 vs 17.0). USB扩展屏's advantage is update cadence (daily vs every 3 months). On price, ads and device support there is nothing between them.

Both are free to download. USB扩展屏 sells 1 one-off in-app purchase. 掌上购电 asks for nothing beyond the download.

掌上购电 ships an update every 3 months, USB扩展屏 daily. The most recent releases landed on October 7, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | 掌上购电 | USB扩展屏 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Daily** |
| Size | 42 MB | 0 MB |
| Requires iOS | **9.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SHANGHAI INBESTECH CO.,LTD](https://appshunter.io/developer/1175209227) | [晓满 李](https://appshunter.io/developer/1515867430) |

## What reviewers say

### 掌上购电

[App page](https://appshunter.io/ios/app/id1522186604)

**Features:** macOS Compatibility

**In-app purchases:** none


### USB扩展屏

[App page](https://appshunter.io/ios/app/usb/id6502822709)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 完整版 | $0.99 | one-time |


## Frequently asked questions

### Is 掌上购电 free?

掌上购电 is free to download, with no in-app purchases.

### Is USB扩展屏 free?

USB扩展屏 is free to download, with in-app purchases available.

### Do 掌上购电 or USB扩展屏 have ads?

Neither 掌上购电 nor USB扩展屏 shows ads.

### Which is updated more often, 掌上购电 or USB扩展屏?

掌上购电 ships an update every 3 months, and USB扩展屏 daily. Most recently, 掌上购电 was updated on October 7, 2026 and USB扩展屏 on October 1, 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.*