# Secret Diary with Locks vs AI PDF Reader

The clearest difference is ads: Secret Diary with Locks at none against AI PDF Reader's shown. AI PDF Reader's advantage is update cadence (daily vs every 3 months) and iOS requirement (14.0 vs 16.0). On price, in-app purchases, monetization model and device support there is nothing between them.

Both are free to download. Secret Diary with Locks sells 1 in-app purchase, starting at $0.99 per year and AI PDF Reader sells 2 in-app purchases, starting at $9.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Secret Diary with Locks ships an update every 3 months, AI PDF Reader daily. The most recent releases landed on October 1, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Secret Diary with Locks | AI PDF Reader |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/ai-pdf-reader-scan-document/id6738639846/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | **Daily** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 10 MB | 33 MB |
| Requires iOS | 16.0 | **14.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Harshad Jadav](https://appshunter.io/developer/1687259507) | [Shenzhen Yicheng Information Technology Co., Ltd](https://appshunter.io/developer/1689358660) |

## What reviewers say

### Secret Diary with Locks

[App page](https://appshunter.io/ios/app/secret-diary-with-locks/id6449743044)

Securely record your thoughts, memories, and personal moments with this private journal app. Protect your entries with a password, PIN, or biometric authentication. All data is stored locally and encrypted for complete privacy.

**Highlights:** Password, PIN, or biometric unlock, AES 256-bit encryption, Offline local storage, Unlimited entries, Advanced search, No internet permission

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Ad-Free - Annual | $0.99 | per year |


### AI PDF Reader

[App page](https://appshunter.io/ios/app/ai-pdf-reader-scan-document/id6738639846)

Easily scan, convert, and organize documents with your phone's camera. Turn images into PDFs, view multiple file formats, and categorize your files automatically. Designed for students, professionals, and home users to improve work efficiency and simplify daily tasks.

**Highlights:** Scan documents to PDF, Convert images to PDF, View multi-format files, Organized file categorization, File favorites, History tracking

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Membership | $9.99 | per 7 days |
| Yearly Membership | $39.99 | per year |


## Frequently asked questions

### Is Secret Diary with Locks free?

Secret Diary with Locks is free to download, with in-app purchases available.

### Is AI PDF Reader free?

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

### Do Secret Diary with Locks or AI PDF Reader have ads?

AI PDF Reader shows ads; Secret Diary with Locks does not.

### Which is updated more often, Secret Diary with Locks or AI PDF Reader?

Secret Diary with Locks ships an update every 3 months, and AI PDF Reader daily. Most recently, Secret Diary with Locks was updated on October 1, 2026 and AI PDF Reader on October 3, 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.*