# QI Calculator vs ToolsUnitConverter

The clearest difference is in-app purchases: ToolsUnitConverter at none against QI Calculator's 2. ToolsUnitConverter also leads on update cadence (every 5 days vs every 3 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. QI Calculator sells 2 one-off in-app purchases. ToolsUnitConverter asks for nothing beyond the download.

QI Calculator ships an update every 3 weeks, ToolsUnitConverter every 5 days. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | QI Calculator | ToolsUnitConverter |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 5 days** |
| Size | 129 MB | 3 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [shouhui qi](https://appshunter.io/developer/1185710456) | [成 熊](https://appshunter.io/developer/1642462750) |

## What reviewers say

### QI Calculator

[App page](https://appshunter.io/ios/app/qi-calculator/id6476379861)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Theme | $0.99 | one-time |
| Theme Blue Sky | $0.99 | one-time |


### ToolsUnitConverter

[App page](https://appshunter.io/ios/app/toolsunitconverter/id6754634175)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases:** none


## Frequently asked questions

### Is QI Calculator free?

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

### Is ToolsUnitConverter free?

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

### Do QI Calculator or ToolsUnitConverter have ads?

Neither QI Calculator nor ToolsUnitConverter shows ads.

### Which is updated more often, QI Calculator or ToolsUnitConverter?

QI Calculator ships an update every 3 weeks, and ToolsUnitConverter every 5 days. Most recently, QI Calculator was updated on October 25, 2026 and ToolsUnitConverter on October 24, 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.*