# ObsiKO vs Nook

The clearest difference is device support: ObsiKO at 4 against Nook's 2. ObsiKO also leads on iOS requirement (15.1 vs 18.0). On price, update cadence, ads 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.

ObsiKO ships an update every 6 days, Nook every 3 days. Both last shipped on October 10, 2026.

## The numbers

| Metric | ObsiKO | Nook |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 days | **Every 3 days** |
| Size | 75 MB | 16 MB |
| Requires iOS | **15.1** | 18.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Hyojin Kim](https://appshunter.io/developer/6783405453) | [KANG SEUNGHYUN](https://appshunter.io/developer/6797773160) |

## What reviewers say

### ObsiKO

[App page](https://appshunter.io/ios/app/obsiko-ai-note-plus-mindmap/id6783405451)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### Nook

[App page](https://appshunter.io/ios/app/nook-read-write-own/id6797773158)

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

**In-app purchases:** none


## Frequently asked questions

### Is ObsiKO free?

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

### Is Nook free?

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

### Do ObsiKO or Nook have ads?

Neither ObsiKO nor Nook shows ads.

### Which is updated more often, ObsiKO or Nook?

ObsiKO ships an update every 6 days, and Nook every 3 days. Most recently, ObsiKO was updated on October 10, 2026 and Nook on October 10, 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.*