# Length Converter vs Smart Diffuser

The clearest difference is monetization model: Smart Diffuser at free against Length Converter's paid. Smart Diffuser also leads on update cadence (every 5 months vs every 72 months) and rating (5.0 vs 4.8). Length Converter's advantage is ratings volume (12 vs 3) and iOS requirement (13.4 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Smart Diffuser holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 12 and 3 respectively.

Length Converter ships an update every 72 months, Smart Diffuser every 5 months. The most recent releases landed on August 25, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | Length Converter | Smart Diffuser |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (12 ratings)](https://appshunter.io/ios/app/length-converter/id1533575399/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/smart-diffuser/id6502768383/reviews)** |
| Number of ratings | **12** | 3 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 72 months | **Every 5 months** |
| Monetization | Paid | **Free** |
| Size | 2 MB | 3 MB |
| Requires iOS | **13.4** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Anna Filobok](https://appshunter.io/developer/1613515832) | [Shenzhen Shengmu Technology Co., Ltd.](https://appshunter.io/developer/1746717166) |

## What reviewers say

### Length Converter

[App page](https://appshunter.io/ios/app/length-converter/id1533575399)

Easily convert lengths between various units including feet, inches, meters, decimeters, centimeters, and millimeters. This tool is designed for quick and accurate conversions for a wide range of users.

**Highlights:** Converts feet, inches, meters, decimeters, centimeters, millimeters, Fast and accurate conversions, User-friendly interface, Supports multiple units

**Features:** macOS Compatibility

**In-app purchases:** none


### Smart Diffuser

[App page](https://appshunter.io/ios/app/smart-diffuser/id6502768383)

Control your aroma diffuser remotely via Bluetooth. Adjust power, lighting, intensity, and set custom schedules. Reset your device directly from your phone.

**Highlights:** Bluetooth connectivity, Power control, Atmosphere light adjustment, Intensity settings, Schedule setup, Device reset

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Length Converter free?

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

### Is Smart Diffuser free?

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

### Which has better reviews, Length Converter or Smart Diffuser?

Smart Diffuser is rated higher. Length Converter averages 4.8 out of 5 from 12 ratings, while Smart Diffuser averages 5.0 from 3 ratings.

### Do Length Converter or Smart Diffuser have ads?

Neither Length Converter nor Smart Diffuser shows ads.

### Which is updated more often, Length Converter or Smart Diffuser?

Length Converter ships an update every 72 months, and Smart Diffuser every 5 months. Most recently, Length Converter was updated on August 25, 2026 and Smart Diffuser on September 18, 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.*