# XT UART vs Little Grey Book

The clearest difference is iOS requirement: XT UART at 13.0 against Little Grey Book's 17.0. 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.

XT UART ships an update every 4 months, Little Grey Book every 3 months. The most recent releases landed on October 16, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | XT UART | Little Grey Book |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/little-grey-book/id6499083339/reviews)** |
| Number of ratings | — | **2** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 3 months** |
| Monetization | — | Free |
| Size | 6 MB | 13 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 9+ |
| Developer | [Shenzhen Lanke Xuntong Technology Co., Ltd.](https://appshunter.io/developer/640898259) | [niv ben-porath](https://appshunter.io/developer/896424268) |

## What reviewers say

### XT UART

[App page](https://appshunter.io/ios/app/xt-uart/id1448659811)

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

**In-app purchases:** none


### Little Grey Book

[App page](https://appshunter.io/ios/app/little-grey-book/id6499083339)

Enhance your Agatha Christie reading experience with a companion app. Track your progress, take notes with text scanning, and test your detective skills with a "Whodunnit Challenge." Explore the complete novel collection and personalize your reading journey.

**Highlights:** Whodunnit Challenge, Text scanning note-taking, Home screen widgets, Complete novel collection, Monthly read notifications, Personalization options, Book filtering by status

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is XT UART free?

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

### Is Little Grey Book free?

Little Grey Book is free to download, with no in-app purchases.

### Do XT UART or Little Grey Book have ads?

Neither XT UART nor Little Grey Book shows ads.

### Which is updated more often, XT UART or Little Grey Book?

XT UART ships an update every 4 months, and Little Grey Book every 3 months. Most recently, XT UART was updated on October 16, 2026 and Little Grey Book on October 4, 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.*