# Sauersack vs ZČU

The clearest difference is update cadence: ZČU at every 4 weeks against Sauersack's every 12 months. Sauersack's advantage is iOS requirement (13.0 vs 17.0). 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.

Sauersack ships an update every 12 months, ZČU every 4 weeks. The most recent releases landed on November 3, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Sauersack | ZČU |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 12 months | **Every 4 weeks** |
| Size | 40 MB | 18 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [VISUALIO s.r.o.](https://appshunter.io/developer/1402599204) | [Západočeská univerzita v Plzni](https://appshunter.io/developer/1644929491) |

## What reviewers say

### Sauersack

[App page](https://appshunter.io/ios/app/sauersack/id1592706324)

**Features:** macOS Compatibility

**In-app purchases:** none


### ZČU

[App page](https://appshunter.io/ios/app/zcu/id6780949487)

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

**In-app purchases:** none


## Frequently asked questions

### Is Sauersack free?

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

### Is ZČU free?

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

### Do Sauersack or ZČU have ads?

Neither Sauersack nor ZČU shows ads.

### Which is updated more often, Sauersack or ZČU?

Sauersack ships an update every 12 months, and ZČU every 4 weeks. Most recently, Sauersack was updated on November 3, 2026 and ZČU on October 7, 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.*