# USB Mobile Disk vs Little Grey Book

The clearest difference is price: Little Grey Book at Free against USB Mobile Disk's $0.99. Little Grey Book also leads on ads (none vs shown) and rating (4.5 vs 4.3). USB Mobile Disk's advantage is device support (3 vs 1) and iOS requirement (12.0 vs 17.0). On ratings volume, update cadence and in-app purchases there is nothing between them.

Little Grey Book is free to download; USB Mobile Disk costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Little Grey Book holds the better App Store score, 4.5 against 4.3. Both are backed by a comparable volume of ratings — 10 and 4 respectively.

Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on October 24, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | USB Mobile Disk | Little Grey Book |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [4.3 (10 ratings)](https://appshunter.io/ios/app/usb-mobile-disk/id505848112/reviews) | **[4.5 (4 ratings)](https://appshunter.io/ios/app/little-grey-book/id6499083339/reviews)** |
| Number of ratings | **10** | 4 |
| Positive reviews | 62.5% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 3 months | Every 3 months |
| Monetization | Paid | **Free** |
| Size | 28 MB | 13 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 9+ |
| Developer | [Raphael Odermatt](https://appshunter.io/developer/403027529) | [niv ben-porath](https://appshunter.io/developer/896424268) |

## What reviewers say

### USB Mobile Disk

[App page](https://appshunter.io/ios/app/usb-mobile-disk/id505848112)

This app turns your iPhone or iPad into a portable storage device, allowing you to carry documents, music, and videos. It features a built-in file manager, music player, PDF reader, and supports various file transfer methods.

**Highlights:** Portable storage for iPhone/iPad, Advanced file manager, Background music player, PDF reader, Gallery import/export, FTP and HTTP file access, ZIP file creation/extraction

**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 USB Mobile Disk free?

USB Mobile Disk costs $0.99, with no in-app purchases.

### Is Little Grey Book free?

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

### Which has better reviews, USB Mobile Disk or Little Grey Book?

Little Grey Book is rated higher. USB Mobile Disk averages 4.3 out of 5 from 10 ratings, while Little Grey Book averages 4.5 from 4 ratings.

### Do USB Mobile Disk or Little Grey Book have ads?

USB Mobile Disk shows ads; Little Grey Book does not.

### Which is updated more often, USB Mobile Disk or Little Grey Book?

USB Mobile Disk ships an update every 3 months, and Little Grey Book every 3 months. Most recently, USB Mobile Disk was updated on October 24, 2026 and Little Grey Book on October 21, 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.*