# Performance Dynamics vs The Nook Sauna

The clearest difference is update cadence: The Nook Sauna at every 3 months against Performance Dynamics's every 9 months. The Nook Sauna also leads on device support. On price, in-app purchases and iOS requirement there is nothing between them.

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

Performance Dynamics ships an update every 9 months, The Nook Sauna every 3 months. The most recent releases landed on September 7, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | Performance Dynamics | The Nook Sauna |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | — | No |
| Update frequency | Every 9 months | **Every 3 months** |
| Size | 55 MB | 42 MB |
| Requires iOS | **14.0** | 15.1 |
| Devices | — | **iPhone, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [TeamUp Sports](https://appshunter.io/developer/1449504626) | [Frankie Dolphin](https://appshunter.io/developer/1833793671) |

## What reviewers say

### Performance Dynamics

[App page](https://appshunter.io/ios/app/performance-dynamics/id6447365555)

**In-app purchases:** none


### The Nook Sauna

[App page](https://appshunter.io/ios/app/the-nook-sauna/id6767178289)

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

**In-app purchases:** none


## Frequently asked questions

### Is Performance Dynamics free?

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

### Is The Nook Sauna free?

The Nook Sauna is free to download, with no in-app purchases.

### Which is updated more often, Performance Dynamics or The Nook Sauna?

Performance Dynamics ships an update every 9 months, and The Nook Sauna every 3 months. Most recently, Performance Dynamics was updated on September 7, 2026 and The Nook Sauna on September 14, 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.*