# PDF Reader vs Knife Sharpening

The clearest difference is in-app purchases: Knife Sharpening at none against PDF Reader's 1. Knife Sharpening also leads on ads (none vs shown). On price, device support and iOS requirement there is nothing between them.

Both are free to download. PDF Reader sells 1 one-off in-app purchase. Knife Sharpening asks for nothing beyond the download.

## The numbers

| Metric | PDF Reader | Knife Sharpening |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Weekly | — |
| Size | 9 MB | 4 MB |
| Requires iOS | 16.6 | **16.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Rajesh Ray](https://appshunter.io/developer/1853271111) | [Jack Kelley](https://appshunter.io/developer/6793921106) |

## What reviewers say

### PDF Reader

[App page](https://appshunter.io/ios/app/pdf-reader-auto-scroll-and-scan/id6755335926)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Lifetime | $9.99 | one-time |


### Knife Sharpening

[App page](https://appshunter.io/ios/app/knife-sharpening/id6793920714)

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

**In-app purchases:** none


## Frequently asked questions

### Is PDF Reader free?

PDF Reader is free to download, with in-app purchases available.

### Is Knife Sharpening free?

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

### Do PDF Reader or Knife Sharpening have ads?

PDF Reader shows ads; Knife Sharpening does not.

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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.*