# PDF Notes Pro vs Natural Scientific Calculator

The clearest difference is review sentiment: Natural Scientific Calculator at 66% against PDF Notes Pro's 13%. Natural Scientific Calculator also leads on price (Free vs $4.99) and rating (4.6 vs 1.7). PDF Notes Pro's advantage is in-app purchases (none vs 3) and iOS requirement (13.0 vs 15.0). On ads and device support there is nothing between them.

Natural Scientific Calculator is free to download; PDF Notes Pro costs $4.99 up front. Natural Scientific Calculator sells 3 in-app purchases, starting at $0.49 per month. PDF Notes Pro asks for nothing beyond the download.

Natural Scientific Calculator holds the better App Store score, 4.6 against 1.7. That said, the two scores are not equally well evidenced: Natural Scientific Calculator has 95 ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 13% of PDF Notes Pro's written reviews are positive against 66% of Natural Scientific Calculator's.

PDF Notes Pro ships an update every 3 weeks, Natural Scientific Calculator weekly. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | PDF Notes Pro | Natural Scientific Calculator |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | [1.7 (6 ratings)](https://appshunter.io/ios/app/pdf-notes-pro/id852698318/reviews) | **[4.6 (95 ratings)](https://appshunter.io/ios/app/natural-scientific-calculator/id1221737584/reviews)** |
| Number of ratings | 6 | **95** |
| Positive reviews | 12.5% of reviews | **66.2% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Weekly** |
| Monetization | Paid | **Freemium** |
| Size | 40 MB | 83 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [UMateY](https://appshunter.io/developer/327433577) | [Stultus Studios Pty Ltd](https://appshunter.io/developer/1221737583) |

## What reviewers say

### PDF Notes Pro

[App page](https://appshunter.io/ios/app/pdf-notes-pro/id852698318)

Transform your iOS device into a digital notebook for annotating and managing PDF documents. Easily add handwritten notes, highlights, and drawings directly onto PDFs, and organize your files with a built-in management system. Share, print, and search your documents and notes with ease.

**Highlights:** Handwritten notes with audio recording, PDF annotation (highlight, underline, strikeout), Freehand drawing and signing, Full-text search within PDFs and notes, Built-in file management, PDF sharing and printing

**Features:** Vision Pro support

**In-app purchases:** none


### Natural Scientific Calculator

[App page](https://appshunter.io/ios/app/natural-scientific-calculator/id1221737584)

This app offers a natural way to input mathematical equations, similar to writing them on paper. It features intuitive editing with swipe gestures and pinch-to-zoom for complex expressions. Save frequently used equations for quick access.

**Highlights:** Natural input for equations, Swipe to edit and pinch to zoom, History and favorites for equations, Fractions, roots, and exponents, Radians and degrees support, Decimal to fraction conversion

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| NSC Plus Monthly Subscription | $0.49 | per month |
| NSC Plus Annual Subscription | $3.99 | per year |
| NSC Plus | $7.99 | one-time |

**What reviewers like**

- 👍 Intuitive and user-friendly interface
- 📐 Natural display with equation editing
- 🚀 Fast and efficient calculations
- 🎓 Excellent for students and engineers
- ✨ Clean, simple design compared to competitors

**What reviewers complain about**

- 🐛 Frequent crashes and freezing
- ❌ Incorrect trigonometric calculations
- 📵 Excessive pop-up notifications requesting reviews
- 💰 Expensive premium version
- 📺 Intrusive and loud advertisements

**Reported bugs**

- Math error on all calculations (widespread issue from late 2022-2023)
- App freezes during startup or tutorial
- Crashes during complex calculations
- Incorrect inverse trigonometric function results
- Incorrect sine, cosine, tangent calculations

**Requested features**

- Dark mode or dark theme option
- Physical keyboard support
- Copy and paste functionality
- History or ticker of previous calculations
- Double and triple zero buttons (00, 000)


## Frequently asked questions

### Is PDF Notes Pro free?

PDF Notes Pro costs $4.99, with no in-app purchases.

### Is Natural Scientific Calculator free?

Natural Scientific Calculator is free to download, with in-app purchases available.

### Which has better reviews, PDF Notes Pro or Natural Scientific Calculator?

Natural Scientific Calculator is rated higher. PDF Notes Pro averages 1.7 out of 5 from 6 ratings, while Natural Scientific Calculator averages 4.6 from 95 ratings.

### Do PDF Notes Pro or Natural Scientific Calculator have ads?

Neither PDF Notes Pro nor Natural Scientific Calculator shows ads.

### Which is updated more often, PDF Notes Pro or Natural Scientific Calculator?

PDF Notes Pro ships an update every 3 weeks, and Natural Scientific Calculator weekly. Most recently, PDF Notes Pro was updated on November 1, 2026 and Natural Scientific Calculator on November 2, 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.*