# LUX vs CalToDo

The clearest difference is in-app purchases: CalToDo at none against LUX's 2. CalToDo also leads on ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. LUX sells 2 in-app purchases, starting at $1.99 per month. CalToDo asks for nothing beyond the download.

LUX ships an update every 2 weeks, CalToDo fortnightly. The most recent releases landed on October 30, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | LUX | CalToDo |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/lux-illuminance-meter/id1631156210/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 2 weeks** | Fortnightly |
| Monetization | Free with in-app purchases | — |
| Size | 17 MB | 1 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [koji torishima](https://appshunter.io/developer/1622793467) | [Yuichiro Nakano](https://appshunter.io/developer/1881945078) |

## What reviewers say

### LUX

[App page](https://appshunter.io/ios/app/lux-illuminance-meter/id1631156210)

Measure ambient light levels in lux or foot-candles instantly. Useful for photography, plant care, or verifying brightness for various tasks. Offers advanced features like color temperature and measurement history for premium users.

**Highlights:** Instant lux measurement, Color temperature (CCT) reading, Foot-candle unit toggle, Min/Avg/Max lux tracking, Measurement history (Premium), CSV export (Premium)

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Plan | $1.99 | per month |
| Yearly Plan | $11.99 | per year |


### CalToDo

[App page](https://appshunter.io/ios/app/caltodo/id6760019258)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is LUX free?

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

### Is CalToDo free?

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

### Do LUX or CalToDo have ads?

LUX shows ads; CalToDo does not.

### Which is updated more often, LUX or CalToDo?

LUX ships an update every 2 weeks, and CalToDo fortnightly. Most recently, LUX was updated on October 30, 2026 and CalToDo on October 25, 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.*