# 计算器 EMMO vs Hardness Conversion Master

The clearest difference is price: Hardness Conversion Master at Free against 计算器 EMMO's $1.99. Hardness Conversion Master also leads on update cadence (every 3 days vs monthly). 计算器 EMMO's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support there is nothing between them.

Hardness Conversion Master is free to download; 计算器 EMMO costs $1.99 up front. Hardness Conversion Master sells 1 one-off in-app purchase. 计算器 EMMO asks for nothing beyond the download.

计算器 EMMO ships an update monthly, Hardness Conversion Master every 3 days. The most recent releases landed on October 27, 2026 and October 22, 2026 respectively.

## The numbers

| Metric | 计算器 EMMO | Hardness Conversion Master |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[5.0 (20 ratings)](https://appshunter.io/ios/app/emmo/id1605744253/reviews)** | — |
| Number of ratings | **20** | — |
| Positive reviews | 85.2% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Every 3 days** |
| Monetization | Paid | — |
| Size | 10 MB | 259 MB |
| Requires iOS | **13.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [EMMO Corp.](https://appshunter.io/developer/1507868195) | [POYU WANG](https://appshunter.io/developer/1883764660) |

## What reviewers say

### 计算器 EMMO

[App page](https://appshunter.io/ios/app/emmo/id1605744253)

A professional scientific calculator with a user-friendly interface and customizable themes. It offers advanced functions beyond the standard system calculator, along with a history log for easy access to past calculations.

**Highlights:** Advanced scientific functions, Customizable themes, History log, Multiple sound effects, Smart and convenient operation

**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 计算器 EMMO free?

计算器 EMMO costs $1.99, with no in-app purchases.

### Is Hardness Conversion Master free?

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

### Do 计算器 EMMO or Hardness Conversion Master have ads?

Hardness Conversion Master shows ads; 计算器 EMMO does not.

### Which is updated more often, 计算器 EMMO or Hardness Conversion Master?

计算器 EMMO ships an update monthly, and Hardness Conversion Master every 3 days. Most recently, 计算器 EMMO was updated on October 27, 2026 and Hardness Conversion Master on October 22, 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.*