# Double Unit Converter vs Smart Unit Conversion

The clearest difference is in-app purchases: Double Unit Converter at none against Smart Unit Conversion's 1. Double Unit Converter also leads on ads (none vs shown) and update cadence (monthly vs every 15 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Smart Unit Conversion sells 1 in-app purchase, starting at $1.99 per year. Double Unit Converter asks for nothing beyond the download.

Double Unit Converter ships an update monthly, Smart Unit Conversion every 15 months. The most recent releases landed on October 2, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Double Unit Converter | Smart Unit Conversion |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Monthly** | Every 15 months |
| Size | 9 MB | 41 MB |
| Requires iOS | **12.0** | 13.4 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [MIHAIL MILUSHEV](https://appshunter.io/developer/648847538) | [Yui Lau](https://appshunter.io/developer/1791465155) |

## What reviewers say

### Double Unit Converter

[App page](https://appshunter.io/ios/app/double-unit-converter/id1451391414)

**Features:** macOS Compatibility

**In-app purchases:** none


### Smart Unit Conversion

[App page](https://appshunter.io/ios/app/smart-unit-conversion/id1643381985)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Year | $1.99 | per year |


## Frequently asked questions

### Is Double Unit Converter free?

Double Unit Converter is free to download, with no in-app purchases.

### Is Smart Unit Conversion free?

Smart Unit Conversion is free to download, with in-app purchases available.

### Do Double Unit Converter or Smart Unit Conversion have ads?

Smart Unit Conversion shows ads; Double Unit Converter does not.

### Which is updated more often, Double Unit Converter or Smart Unit Conversion?

Double Unit Converter ships an update monthly, and Smart Unit Conversion every 15 months. Most recently, Double Unit Converter was updated on October 2, 2026 and Smart Unit Conversion on October 8, 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.*