# Diffraction Grating Calculator vs Math Keyboard

The clearest difference is price: Math Keyboard at Free against Diffraction Grating Calculator's $2.99. Math Keyboard also leads on update cadence (every 5 weeks vs every 29 months). Diffraction Grating Calculator's advantage is in-app purchases (none vs 1) and iOS requirement (13 vs 26.2). On ads and device support there is nothing between them.

Math Keyboard is free to download; Diffraction Grating Calculator costs $2.99 up front. Math Keyboard sells 1 one-off in-app purchase. Diffraction Grating Calculator asks for nothing beyond the download.

Diffraction Grating Calculator ships an update every 29 months, Math Keyboard every 5 weeks. The most recent releases landed on September 29, 2026 and September 26, 2026 respectively.

## The numbers

| Metric | Diffraction Grating Calculator | Math Keyboard |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | — | **[2.5 (4 ratings)](https://appshunter.io/ios/app/math-keyboard-formula-input/id6757350527/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 29 months | **Every 5 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 1 MB | 2 MB |
| Requires iOS | **13** | 26.2 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Yuta Nishimatsu](https://appshunter.io/developer/1480004995) |

## What reviewers say

### Diffraction Grating Calculator

[App page](https://appshunter.io/ios/app/diffraction-grating-calculator/id1413088894)

**Features:** macOS Compatibility

**In-app purchases:** none


### Math Keyboard

[App page](https://appshunter.io/ios/app/math-keyboard-formula-input/id6757350527)

This custom keyboard simplifies typing mathematical and physics symbols, including Greek letters and superscripts/subscripts. Seamlessly input formulas into any app without needing to copy and paste from external sources. Enhance your notes, reports, and messages with ease.

**Highlights:** Superscripts/subscripts for numbers, letters, and symbols, Greek letters support, Wide variety of math symbols, Familiar keyboard layout, Quick tab switching, Cursor control via long-press

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| MathKeyboard Pro | $5.99 | one-time |


## Frequently asked questions

### Is Diffraction Grating Calculator free?

Diffraction Grating Calculator costs $2.99, with no in-app purchases.

### Is Math Keyboard free?

Math Keyboard is free to download, with in-app purchases available.

### Do Diffraction Grating Calculator or Math Keyboard have ads?

Neither Diffraction Grating Calculator nor Math Keyboard shows ads.

### Which is updated more often, Diffraction Grating Calculator or Math Keyboard?

Diffraction Grating Calculator ships an update every 29 months, and Math Keyboard every 5 weeks. Most recently, Diffraction Grating Calculator was updated on September 29, 2026 and Math Keyboard on September 26, 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.*