# Omaha System Reference II vs Attendi

The clearest difference is update cadence: Omaha System Reference II at weekly against Attendi's fortnightly. 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.

Omaha System Reference II ships an update weekly, Attendi fortnightly. Both last shipped on October 25, 2026.

## The numbers

| Metric | Omaha System Reference II | Attendi |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Weekly** | Fortnightly |
| Size | 18 MB | 16 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Ecare Innovatie B.V.](https://appshunter.io/developer/1267905240) | [Attendi](https://appshunter.io/developer/1609387175) |

## What reviewers say

### Omaha System Reference II

[App page](https://appshunter.io/ios/app/omaha-system-reference-ii/id1450603395)

**Features:** Vision Pro support

**In-app purchases:** none


### Attendi

[App page](https://appshunter.io/ios/app/attendi/id6757230193)

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

**In-app purchases:** none


## Frequently asked questions

### Is Omaha System Reference II free?

Omaha System Reference II is free to download, with no in-app purchases.

### Is Attendi free?

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

### Do Omaha System Reference II or Attendi have ads?

Neither Omaha System Reference II nor Attendi shows ads.

### Which is updated more often, Omaha System Reference II or Attendi?

Omaha System Reference II ships an update weekly, and Attendi fortnightly. Most recently, Omaha System Reference II was updated on October 25, 2026 and Attendi on October 25, 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.*