# RealXV6 vs FocusOne

The clearest difference is in-app purchases: RealXV6 at none against FocusOne's 2. FocusOne's advantage is update cadence (every 2 days vs every 4 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. FocusOne sells 2 in-app purchases, starting at $1.99 per month. RealXV6 asks for nothing beyond the download.

RealXV6 ships an update every 4 months, FocusOne every 2 days. Both last shipped on October 12, 2026.

## The numbers

| Metric | RealXV6 | FocusOne |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/realxv6/id6757357040/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 days** |
| Monetization | Free | — |
| Size | 15 MB | 58 MB |
| Requires iOS | 17.2 | **16.4** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Zheng Fang](https://appshunter.io/developer/1258046278) | [泉璋 程](https://appshunter.io/developer/6788467524) |

## What reviewers say

### RealXV6

[App page](https://appshunter.io/ios/app/realxv6/id6757357040)

Explore the legendary Lions' Commentary on UNIX 6th Edition by bringing its source code to life. This app provides an interactive virtual machine to dynamically experience OS kernel operations, offering source-level debugging and precise execution control for a deeper understanding.

**Highlights:** Interactive virtual machine for OS study, Source-level debugging, Precise execution control (step in, over, out), Trace context switching and interrupts, Simplified 8086 architecture, Portable OS laboratory

**Features:** macOS Compatibility

**In-app purchases:** none


### FocusOne

[App page](https://appshunter.io/ios/app/focusone-learn-new-things/id6788748794)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FocusOne Pro | $1.99 | per month |
| FocusOne Pro | $9.99 | per year |


## Frequently asked questions

### Is RealXV6 free?

RealXV6 is free to download, with no in-app purchases.

### Is FocusOne free?

FocusOne is free to download, with in-app purchases available.

### Do RealXV6 or FocusOne have ads?

Neither RealXV6 nor FocusOne shows ads.

### Which is updated more often, RealXV6 or FocusOne?

RealXV6 ships an update every 4 months, and FocusOne every 2 days. Most recently, RealXV6 was updated on October 12, 2026 and FocusOne on October 12, 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.*