# PDF Protector vs OTC Memo

The clearest difference is in-app purchases: OTC Memo at none against PDF Protector's 3. OTC Memo also leads on update cadence (weekly vs every 3 weeks) and iOS requirement (16.4 vs 18.0). On price, ads and device support there is nothing between them.

Both are free to download. PDF Protector sells 3 one-off in-app purchases. OTC Memo asks for nothing beyond the download.

PDF Protector ships an update every 3 weeks, OTC Memo weekly. Both last shipped on October 17, 2026.

## The numbers

| Metric | PDF Protector | OTC Memo |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/pdf-protector/id566631581/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 71.1% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Weekly** |
| Monetization | Free | — |
| Size | 9 MB | 41 MB |
| Requires iOS | 18.0 | **16.4** |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Witt](https://appshunter.io/developer/1438848391) | [Katsushi Kawamori](https://appshunter.io/developer/1771822715) |

## What reviewers say

### PDF Protector

[App page](https://appshunter.io/ios/app/pdf-protector/id566631581)

Secure your PDF documents with robust password protection and encryption. This tool allows you to restrict printing, copying, and content extraction, while also enabling decryption of protected files. Protect sensitive information quickly and reliably.

**Highlights:** Encrypt PDF files with password protection, Restrict printing and copying, Decrypt protected PDFs, Create reusable security profiles, Protect multiple files at once, Fast and intuitive interface

**Features:** Family Sharing, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Version for iPhone & iPad | $4.99 | one-time |
| Full Version for Mac | $9.99 | one-time |
| Full Version for All Devices | $12.99 | one-time |


### OTC Memo

[App page](https://appshunter.io/ios/app/otc-memo/id6751605864)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is PDF Protector free?

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

### Is OTC Memo free?

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

### Do PDF Protector or OTC Memo have ads?

Neither PDF Protector nor OTC Memo shows ads.

### Which is updated more often, PDF Protector or OTC Memo?

PDF Protector ships an update every 3 weeks, and OTC Memo weekly. Most recently, PDF Protector was updated on October 17, 2026 and OTC Memo on October 17, 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.*