# Napier's Bones Simulation vs Roughness

The clearest difference is price: Roughness at Free against Napier's Bones Simulation's $1.99. Napier's Bones Simulation's advantage is iOS requirement (12.0 vs 15.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Roughness is free to download; Napier's Bones Simulation costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Napier's Bones Simulation ships an update every 25 months, Roughness every 14 months. The most recent releases landed on October 9, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Napier's Bones Simulation | Roughness |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 25 months | **Every 14 months** |
| Size | 29 MB | 26 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | **iPhone, iPad, iPod, Apple TV** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ventura Educational Systems](https://appshunter.io/developer/371324172) | [Carl Zeiss AG](https://appshunter.io/developer/488066215) |

## What reviewers say

### Napier's Bones Simulation

[App page](https://appshunter.io/ios/app/napiers-bones-simulation/id1093899282)

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

**In-app purchases:** none


### Roughness

[App page](https://appshunter.io/ios/app/roughness/id1356085703)

**In-app purchases:** none


## Frequently asked questions

### Is Napier's Bones Simulation free?

Napier's Bones Simulation costs $1.99, with no in-app purchases.

### Is Roughness free?

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

### Do Napier's Bones Simulation or Roughness have ads?

Neither Napier's Bones Simulation nor Roughness shows ads.

### Which is updated more often, Napier's Bones Simulation or Roughness?

Napier's Bones Simulation ships an update every 25 months, and Roughness every 14 months. Most recently, Napier's Bones Simulation was updated on October 9, 2026 and Roughness on October 6, 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.*