# SmartVUS zn vs SONO USG

The clearest difference is update cadence: SONO USG at every 3 weeks against SmartVUS zn's every 2 months. 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.

SmartVUS zn ships an update every 2 months, SONO USG every 3 weeks. The most recent releases landed on October 11, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | SmartVUS zn | SONO USG |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Size | 9 MB | 276 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [SonopTek Co., Ltd.](https://appshunter.io/developer/1077612429) | [Leltek](https://appshunter.io/developer/1329395835) |

## What reviewers say

### SmartVUS zn

[App page](https://appshunter.io/ios/app/smartvus-zn/id1547566836)

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

**In-app purchases:** none


### SONO USG

[App page](https://appshunter.io/ios/app/sono-usg/id1671961635)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SmartVUS zn free?

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

### Is SONO USG free?

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

### Do SmartVUS zn or SONO USG have ads?

Neither SmartVUS zn nor SONO USG shows ads.

### Which is updated more often, SmartVUS zn or SONO USG?

SmartVUS zn ships an update every 2 months, and SONO USG every 3 weeks. Most recently, SmartVUS zn was updated on October 11, 2026 and SONO USG on October 25, 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.*