# Libre Light Sensor vs Light Spectrometer Wavelength

The clearest difference is rating: Libre Light Sensor at 4.8 against Light Spectrometer Wavelength's 4.2. Libre Light Sensor also leads on in-app purchases (none vs 7) and review sentiment (82% vs 73%). Light Spectrometer Wavelength's advantage is device support (3 vs 1). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Light Spectrometer Wavelength sells 4 in-app purchases, starting at $0.99 per month. Libre Light Sensor asks for nothing beyond the download.

Libre Light Sensor holds the better App Store score, 4.8 against 4.2. Both are backed by a comparable volume of ratings — 113 and 94 respectively. Written reviews point the same way: 82% of Libre Light Sensor's written reviews are positive against 73% of Light Spectrometer Wavelength's.

Libre Light Sensor ships an update every 5 weeks, Light Spectrometer Wavelength every 2 months. The most recent releases landed on October 7, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Libre Light Sensor | Light Spectrometer Wavelength |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (113 ratings)](https://appshunter.io/ios/app/libre-light-sensor/id1644439968/reviews)** | [4.2 (94 ratings)](https://appshunter.io/ios/app/light-spectrometer-wavelength/id6450930820/reviews) |
| Number of ratings | **113** | 94 |
| Positive reviews | **82.4% of reviews** | 72.7% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 2 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 1 MB | 43 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [John Harrington](https://appshunter.io/developer/1603002572) | [Contechity AB](https://appshunter.io/developer/1649290454) |

## What reviewers say

### Libre Light Sensor

[App page](https://appshunter.io/ios/app/libre-light-sensor/id1644439968)

Measure ambient light levels in Lux using your iPhone's camera. Optimize sleep quality by understanding light exposure throughout the day and night.

**Highlights:** Measure light in Lux, Utilizes iPhone camera, Optimize sleep quality, Track light exposure

**In-app purchases:** none


### Light Spectrometer Wavelength

[App page](https://appshunter.io/ios/app/light-spectrometer-wavelength/id6450930820)

This application analyzes light to determine its dominant wavelength in nanometers, frequency in terahertz, and period length in femtoseconds. It provides real-time measurements and allows users to save their findings with notes. The app is designed for measuring colored light sources.

**Highlights:** Measures dominant wavelength (nm), Measures frequency (THz), Measures period length (fs), Real-time measurement, Save measurements with notes, Optional calibration

**Features:** Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Access | $0.99 | per month |
| Full access | $0.99 | per month |
| Full access | $4.99 | per year |
| Full access | $6.99 | one-time |


## Frequently asked questions

### Is Libre Light Sensor free?

Libre Light Sensor is free to download, with no in-app purchases.

### Is Light Spectrometer Wavelength free?

Light Spectrometer Wavelength is free to download, with in-app purchases available.

### Which has better reviews, Libre Light Sensor or Light Spectrometer Wavelength?

Libre Light Sensor is rated higher. Libre Light Sensor averages 4.8 out of 5 from 113 ratings, while Light Spectrometer Wavelength averages 4.2 from 94 ratings.

### Do Libre Light Sensor or Light Spectrometer Wavelength have ads?

Neither Libre Light Sensor nor Light Spectrometer Wavelength shows ads.

### Which is updated more often, Libre Light Sensor or Light Spectrometer Wavelength?

Libre Light Sensor ships an update every 5 weeks, and Light Spectrometer Wavelength every 2 months. Most recently, Libre Light Sensor was updated on October 7, 2026 and Light Spectrometer Wavelength on October 9, 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.*