# Sound function check vs Pier Shell

The clearest difference is ads: Pier Shell at none against Sound function check's shown. Pier Shell also leads on device support (3 vs 1). Sound function check's advantage is iOS requirement (17.6 vs 26.5). On price and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | Sound function check | Pier Shell |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | — | Every 2 weeks |
| Size | 8 MB | 13 MB |
| Requires iOS | **17.6** | 26.5 |
| Devices | iPhone | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Yasushi Tauchi](https://appshunter.io/developer/1819284921) | [Muhamad Nur Asyraaf](https://appshunter.io/developer/1841873975) |

## What reviewers say

### Sound function check

[App page](https://appshunter.io/ios/app/sound-function-check/id6774851912)

**In-app purchases:** none


### Pier Shell

[App page](https://appshunter.io/ios/app/pier-shell/id6801818407)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Sound function check free?

Sound function check is free to download, with no in-app purchases.

### Is Pier Shell free?

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

### Do Sound function check or Pier Shell have ads?

Sound function check shows ads; Pier Shell does not.

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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.*