# School Calculator Pro vs CAJ文献阅读器

The clearest difference is price: CAJ文献阅读器 at Free against School Calculator Pro's $1.99. School Calculator Pro's advantage is in-app purchases (none vs 3) and update cadence (every 2 months vs every 4 months). On ads, device support and iOS requirement there is nothing between them.

CAJ文献阅读器 is free to download; School Calculator Pro costs $1.99 up front. CAJ文献阅读器 sells 3 in-app purchases, starting at $2.99 per month. School Calculator Pro asks for nothing beyond the download.

School Calculator Pro ships an update every 2 months, CAJ文献阅读器 every 4 months. The most recent releases landed on October 25, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | School Calculator Pro | CAJ文献阅读器 |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Positive reviews | — | 65.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 4 months |
| Monetization | — | Freemium |
| Size | 26 MB | 53 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [KrashSoft](https://appshunter.io/developer/1599135484) | [Meitian Trading](https://appshunter.io/developer/1549616114) |

## What reviewers say

### School Calculator Pro

[App page](https://appshunter.io/ios/app/school-calculator-pro/id1614316164)

**In-app purchases:** none


### CAJ文献阅读器

[App page](https://appshunter.io/ios/app/caj/id1669879414)

This app allows you to easily read and convert CAJ, NH, and KDH document formats, commonly used for academic papers from Chinese academic databases. It supports converting these files to PDF or Word, with OCR capabilities for text extraction from scanned images. You can also import files from messaging apps and manage your reading history.

**Highlights:** Read CAJ, NH, KDH formats, Convert CAJ to PDF, Convert CAJ to Word, OCR text recognition, Import from messaging apps, Reading history management

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 月会员 | $2.99 | per month |
| 季会员 | $4.99 | per 3 months |
| 年会员 | $7.99 | per year |


## Frequently asked questions

### Is School Calculator Pro free?

School Calculator Pro costs $1.99, with no in-app purchases.

### Is CAJ文献阅读器 free?

CAJ文献阅读器 is free to download, with in-app purchases available.

### Do School Calculator Pro or CAJ文献阅读器 have ads?

Neither School Calculator Pro nor CAJ文献阅读器 shows ads.

### Which is updated more often, School Calculator Pro or CAJ文献阅读器?

School Calculator Pro ships an update every 2 months, and CAJ文献阅读器 every 4 months. Most recently, School Calculator Pro was updated on October 25, 2026 and CAJ文献阅读器 on November 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.*