# SHSI vs Hardness Conversion Master

The clearest difference is in-app purchases: SHSI at none against Hardness Conversion Master's 1. SHSI also leads on ads (none vs shown) and iOS requirement (15.0 vs 17.6). Hardness Conversion Master's advantage is update cadence (every 3 days vs every 12 months). On price and device support there is nothing between them.

Both are free to download. Hardness Conversion Master sells 1 one-off in-app purchase. SHSI asks for nothing beyond the download.

SHSI ships an update every 12 months, Hardness Conversion Master every 3 days. The most recent releases landed on September 30, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | SHSI | Hardness Conversion Master |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 12 months | **Every 3 days** |
| Size | 24 MB | 259 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [shsse](https://appshunter.io/developer/1049237918) | [POYU WANG](https://appshunter.io/developer/1883764660) |

## What reviewers say

### SHSI

[App page](https://appshunter.io/ios/app/shsi/id6657982140)

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

**In-app purchases:** none


### Hardness Conversion Master

[App page](https://appshunter.io/ios/app/hardness-conversion-master/id6760411989)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | $1.99 | one-time |


## Frequently asked questions

### Is SHSI free?

SHSI is free to download, with no in-app purchases.

### Is Hardness Conversion Master free?

Hardness Conversion Master is free to download, with in-app purchases available.

### Do SHSI or Hardness Conversion Master have ads?

Hardness Conversion Master shows ads; SHSI does not.

### Which is updated more often, SHSI or Hardness Conversion Master?

SHSI ships an update every 12 months, and Hardness Conversion Master every 3 days. Most recently, SHSI was updated on September 30, 2026 and Hardness Conversion Master on October 5, 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.*