# SOS Security vs PDF Document Editor, Read Book

The clearest difference is in-app purchases: SOS Security at none against PDF Document Editor, Read Book's 6. PDF Document Editor, Read Book's advantage is update cadence (every 9 days vs every 18 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. PDF Document Editor, Read Book sells 6 in-app purchases, starting at $1.99 per 7 days. SOS Security asks for nothing beyond the download.

SOS Security ships an update every 18 months, PDF Document Editor, Read Book every 9 days. The most recent releases landed on October 17, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | SOS Security | PDF Document Editor, Read Book |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/pdf-document-editor-read-book/id6504371765/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 18 months | **Every 9 days** |
| Monetization | — | Freemium |
| Size | 197 MB | 33 MB |
| Requires iOS | 16 | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Manolo Milian](https://appshunter.io/developer/1686540764) | [Oleksandr Bilyk](https://appshunter.io/developer/1588574362) |

## What reviewers say

### SOS Security

[App page](https://appshunter.io/ios/app/sos-security/id6463294744)

**Features:** macOS Compatibility

**In-app purchases:** none


### PDF Document Editor, Read Book

[App page](https://appshunter.io/ios/app/pdf-document-editor-read-book/id6504371765)

Edit, sign, and read PDF documents with ease. Add text, images, and signatures, convert files to and from PDF, and scan physical documents into digital format. Manage pages, merge files, and extract text using OCR technology.

**Highlights:** Add text, images, and signatures to PDFs, Read and annotate PDF books, Scan documents to PDF with OCR, Convert files to and from PDF, Merge, split, and reorder PDF pages, Professional e-signature creation and use

**Features:** macOS Compatibility

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PDF Editor: PDF Reader, Sign | $1.99 | per 7 days |
| PDF Editor: PDF Reader, Sign | $2.99 | per 7 days |
| PDF Editor: PDF Reader, Sign | $5.99 | per month |
| PDF Editor: PDF Reader, Sign | $6.99 | per month |
| PDF Editor: PDF Reader, Sign | $24.99 | per year |
| PDF Editor: PDF Reader, Sign | $34.99 | per year |


## Frequently asked questions

### Is SOS Security free?

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

### Is PDF Document Editor, Read Book free?

PDF Document Editor, Read Book is free to download, with in-app purchases available.

### Do SOS Security or PDF Document Editor, Read Book have ads?

Neither SOS Security nor PDF Document Editor, Read Book shows ads.

### Which is updated more often, SOS Security or PDF Document Editor, Read Book?

SOS Security ships an update every 18 months, and PDF Document Editor, Read Book every 9 days. Most recently, SOS Security was updated on October 17, 2026 and PDF Document Editor, Read 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.*