# PDF Reader & PDF Viewer App vs Scientific Engineer Calculator

The clearest difference is price: PDF Reader & PDF Viewer App at Free against Scientific Engineer Calculator's $0.99. Scientific Engineer Calculator's advantage is in-app purchases (none vs 9) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

PDF Reader & PDF Viewer App is free to download; Scientific Engineer Calculator costs $0.99 up front. PDF Reader & PDF Viewer App sells 8 in-app purchases, starting at $4.49 per 7 days. Scientific Engineer Calculator asks for nothing beyond the download.

PDF Reader & PDF Viewer App ships an update monthly, Scientific Engineer Calculator every 5 days. The most recent releases landed on October 24, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | PDF Reader & PDF Viewer App | Scientific Engineer Calculator |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[4.4 (9 ratings)](https://appshunter.io/ios/app/pdf-reader-and-pdf-viewer-app/id6467587935/reviews)** | — |
| Number of ratings | **9** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Monthly | **Every 5 days** |
| Monetization | Free with in-app purchases | — |
| Size | 64 MB | 6 MB |
| Requires iOS | **15.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Nguyen Quy Son](https://appshunter.io/developer/1594539200) | [Yasin Ercan Ozdemir](https://appshunter.io/developer/1883375624) |

## What reviewers say

### PDF Reader & PDF Viewer App

[App page](https://appshunter.io/ios/app/pdf-reader-and-pdf-viewer-app/id6467587935)

Easily read and manage PDF files on your mobile device. Organize documents by renaming, sharing, and bookmarking them for quick access. This user-friendly tool allows you to view ebooks and PDF books anywhere, anytime.

**Highlights:** Read any PDF file, Organize documents, Rename files, Bookmark files, User-friendly interface, Share documents

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly - PDF Reader | $4.49 | per 7 days |
| Weekly - PDF Reader | $4.49 | per 7 days |
| Monthly - PDF Reader | $7.99 | per month |
| Weekly Pro - PDF Reader | $7.99 | per 7 days |
| Monthly Pro - PDF Reader | $9.99 | per month |
| Sale yearly - PDF Reader | $18.99 | per year |
| Yearly - PDF Reader | $31.49 | per year |
| 3 Day free trial - Yearly Pro | $49.99 | per year |


### Scientific Engineer Calculator

[App page](https://appshunter.io/ios/app/scientific-engineer-calculator/id6760608427)

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

**In-app purchases:** none


## Frequently asked questions

### Is PDF Reader & PDF Viewer App free?

PDF Reader & PDF Viewer App is free to download, with in-app purchases available.

### Is Scientific Engineer Calculator free?

Scientific Engineer Calculator costs $0.99, with no in-app purchases.

### Do PDF Reader & PDF Viewer App or Scientific Engineer Calculator have ads?

PDF Reader & PDF Viewer App shows ads; Scientific Engineer Calculator does not.

### Which is updated more often, PDF Reader & PDF Viewer App or Scientific Engineer Calculator?

PDF Reader & PDF Viewer App ships an update monthly, and Scientific Engineer Calculator every 5 days. Most recently, PDF Reader & PDF Viewer App was updated on October 24, 2026 and Scientific Engineer Calculator on October 7, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*