# Shield vs PDF File Protector

The clearest difference is price: Shield at $0.99 against PDF File Protector's $19.99. Shield also leads on in-app purchases (none vs 1) and update cadence (every 3 weeks vs every 2 months). PDF File Protector's advantage is iOS requirement (16.6 vs 26.0). On ads and device support there is nothing between them.

Shield costs $0.99 and PDF File Protector $19.99 up front. PDF File Protector sells 1 one-off in-app purchase. Shield asks for nothing beyond the download.

Shield ships an update every 3 weeks, PDF File Protector every 2 months. The most recent releases landed on September 14, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Shield | PDF File Protector |
| --- | --- | --- |
| Price | **$0.99** | $19.99 |
| Rating | **[4.4 (8 ratings)](https://appshunter.io/ios/app/shield-spam-text-filter/id6503194185/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 90.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | Paid | — |
| Size | 8 MB | 7 MB |
| Requires iOS | 26.0 | **16.6** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [TRILLIWON, Co.](https://appshunter.io/developer/1050731374) | [乐祥 胡](https://appshunter.io/developer/1572365721) |

## What reviewers say

### Shield

[App page](https://appshunter.io/ios/app/shield-spam-text-filter/id6503194185)

This utility app uses AI to filter and categorize SMS messages, blocking spam and organizing your inbox. It offers customizable filters and a privacy-first approach to keep your communications clean and secure.

**Highlights:** AI-driven spam filtering, Privacy-first data handling, Unlimited customizable filters, Intelligent message categorization, Easy setup and user-friendly interface

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

**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 Shield free?

Shield costs $0.99, with no in-app purchases.

### Is PDF File Protector free?

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

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

Neither Shield nor PDF File Protector shows ads.

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

Shield ships an update every 3 weeks, and PDF File Protector every 2 months. Most recently, Shield was updated on September 14, 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.*