# U vs 에스덕

The clearest difference is update cadence: 에스덕 at every 4 days against U's every 4 months. U's advantage is iOS requirement (12.3 vs 15.0). 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.

U ships an update every 4 months, 에스덕 every 4 days. Both last shipped on November 3, 2026.

## The numbers

| Metric | U | 에스덕 |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 days** |
| Monetization | Free | — |
| Size | 8 MB | 86 MB |
| Requires iOS | **12.3** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MIN HO KIM](https://appshunter.io/developer/582570599) | [ZANG YEOB YANG](https://appshunter.io/developer/1706447763) |

## What reviewers say

### U

[App page](https://appshunter.io/ios/app/u-class-student/id1472703543)

This app allows teachers to monitor student devices in real-time, share their PC screen, and facilitate file transfers. It also includes annotation tools and group management features for collaborative learning.

**Highlights:** Real-time student device monitoring, Teacher PC screen sharing, File transfer between students and teachers, Annotation and whiteboard functionality, Student group management, Remote control of student devices

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

**In-app purchases:** none


### 에스덕

[App page](https://appshunter.io/ios/app/id6455375105)

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

**In-app purchases:** none


## Frequently asked questions

### Is U free?

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

### Is 에스덕 free?

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

### Do U or 에스덕 have ads?

Neither U nor 에스덕 shows ads.

### Which is updated more often, U or 에스덕?

U ships an update every 4 months, and 에스덕 every 4 days. Most recently, U was updated on November 3, 2026 and 에스덕 on November 3, 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.*