# Smart Candle vs UnitDeck

The clearest difference is in-app purchases: Smart Candle at none against UnitDeck's 1. Smart Candle also leads on iOS requirement (13.0 vs 17.0). UnitDeck's advantage is update cadence (every 2 weeks vs monthly). On price, ads and device support there is nothing between them.

Both are free to download. UnitDeck sells 1 one-off in-app purchase. Smart Candle asks for nothing beyond the download.

Smart Candle ships an update monthly, UnitDeck every 2 weeks. The most recent releases landed on October 3, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Smart Candle | UnitDeck |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 2 weeks** |
| Size | 47 MB | 3 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SHENZHEN QUANLIANGYU BIOTECHNOLOGY CO.,LTD](https://appshunter.io/developer/1330179432) | [建辉 刘](https://appshunter.io/developer/6790622804) |

## What reviewers say

### Smart Candle

[App page](https://appshunter.io/ios/app/smart-candle/id6751098524)

**Features:** macOS Compatibility

**In-app purchases:** none


### UnitDeck

[App page](https://appshunter.io/ios/app/unitdeck-work-unit-converter/id6792440865)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| UnitDeck Pro – Lifetime | $3.99 | one-time |


## Frequently asked questions

### Is Smart Candle free?

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

### Is UnitDeck free?

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

### Do Smart Candle or UnitDeck have ads?

Neither Smart Candle nor UnitDeck shows ads.

### Which is updated more often, Smart Candle or UnitDeck?

Smart Candle ships an update monthly, and UnitDeck every 2 weeks. Most recently, Smart Candle was updated on October 3, 2026 and UnitDeck on October 2, 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.*