# Smart Green Converter vs UnitStack

The clearest difference is update cadence: UnitStack at every 2 days against Smart Green Converter's every 7 months. Smart Green Converter's advantage is iOS requirement (14.0 vs 18.6). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Smart Green Converter against 5.0 for UnitStack. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

Smart Green Converter ships an update every 7 months, UnitStack every 2 days. The most recent releases landed on October 5, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Smart Green Converter | UnitStack |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/smart-green-converter/id970629053/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/unitstack/id6757423947/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 2 days** |
| Monetization | Free | Free |
| Size | 18 MB | 4 MB |
| Requires iOS | **14.0** | 18.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [The Green Flame Gas Co](https://appshunter.io/developer/1479226447) | [Michael Yang](https://appshunter.io/developer/1866843188) |

## What reviewers say

### Smart Green Converter

[App page](https://appshunter.io/ios/app/smart-green-converter/id970629053)

Easily convert between various units of measurement for gases, including length, power, volume, mass, and pressure. Share your conversion results via email or SMS, or copy them to your notes.

**Highlights:** Unit of Measurement Conversion, Length Units, Power Units, Volume Units, Mass Units, Pressure Units, Share Conversion Results

**Features:** macOS Compatibility

**In-app purchases:** none


### UnitStack

[App page](https://appshunter.io/ios/app/unitstack/id6757423947)

This utility app allows for simultaneous unit and currency conversions, saving your progress and custom units. Its minimalist design ensures a clear and efficient user experience for all your measurement needs.

**Highlights:** Stack multiple conversions, Persistent values, Custom units of measure, Minimalist interface, Custom color themes, Currency conversion

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Smart Green Converter free?

Smart Green Converter is free to download, with no in-app purchases.

### Is UnitStack free?

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

### Which has better reviews, Smart Green Converter or UnitStack?

Smart Green Converter and UnitStack are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.

### Do Smart Green Converter or UnitStack have ads?

Neither Smart Green Converter nor UnitStack shows ads.

### Which is updated more often, Smart Green Converter or UnitStack?

Smart Green Converter ships an update every 7 months, and UnitStack every 2 days. Most recently, Smart Green Converter was updated on October 5, 2026 and UnitStack on October 4, 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.*