# Nasu vs PDF File Protector

The clearest difference is price: Nasu at Free against PDF File Protector's $19.99. Nasu also leads on in-app purchases (none vs 1) and update cadence (fortnightly vs every 2 months). On ads, device support and iOS requirement there is nothing between them.

Nasu is free to download; PDF File Protector costs $19.99 up front. PDF File Protector sells 1 one-off in-app purchase. Nasu asks for nothing beyond the download.

Nasu ships an update fortnightly, PDF File Protector every 2 months. The most recent releases landed on September 11, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Nasu | PDF File Protector |
| --- | --- | --- |
| Price | **Free** | $19.99 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 2 months |
| Size | 9 MB | 7 MB |
| Requires iOS | 17.5 | **16.6** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Zebel OU](https://appshunter.io/developer/882509165) | [乐祥 胡](https://appshunter.io/developer/1572365721) |

## What reviewers say

### Nasu

[App page](https://appshunter.io/ios/app/nasu-therapy-session-notes/id6677000272)

**In-app purchases:** none


### PDF File Protector

[App page](https://appshunter.io/ios/app/pdf-file-protector/id6738285744)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| pdf签名内购 | $9.99 | one-time |


## Frequently asked questions

### Is Nasu free?

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

### Is PDF File Protector free?

PDF File Protector costs $19.99, and also offers in-app purchases.

### Do Nasu or PDF File Protector have ads?

Neither Nasu nor PDF File Protector shows ads.

### Which is updated more often, Nasu or PDF File Protector?

Nasu ships an update fortnightly, and PDF File Protector every 2 months. Most recently, Nasu was updated on September 11, 2026 and PDF File Protector on September 9, 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.*