# H. I. S. vs Sigmakey

The clearest difference is in-app purchases: H. I. S. at none against Sigmakey's 1. H. I. S. also leads on iOS requirement (17.6 vs 26.0). On price, ads and device support there is nothing between them.

Both are free to download. Sigmakey sells 1 one-off in-app purchase. H. I. S. asks for nothing beyond the download.

## The numbers

| Metric | H. I. S. | Sigmakey |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[2.0 (1 ratings)](https://appshunter.io/ios/app/sigmakey-math-keyboard/id6788025133/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | — |
| Monetization | — | Free with in-app purchases |
| Size | 12 MB | 13 MB |
| Requires iOS | **17.6** | 26.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Ayman Agamy](https://appshunter.io/developer/1795479741) | [Andrii Bashta](https://appshunter.io/developer/1547467775) |

## What reviewers say

### H. I. S.

[App page](https://appshunter.io/ios/app/h-i-s/id6785948819)

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

**In-app purchases:** none


### Sigmakey

[App page](https://appshunter.io/ios/app/sigmakey-math-keyboard/id6788025133)

This utility provides a specialized keyboard for typing mathematical expressions, including fractions, roots, and Greek letters, directly within any app. It supports LaTeX, Unicode, and image output, with on-device processing for privacy and speed.

**Highlights:** Full math keyboard layout, Two-dimensional cursor for exponents/numerators, Type LaTeX, Unicode, or rendered image, On-device typesetting, no network required, Symbol search, recent, and favorite symbols

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sigmakey Pro | $9.99 | one-time |


## Frequently asked questions

### Is H. I. S. free?

H. I. S. is free to download, with no in-app purchases.

### Is Sigmakey free?

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

### Do H. I. S. or Sigmakey have ads?

Neither H. I. S. nor Sigmakey shows ads.

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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.*