# Photone vs Libre Light Sensor

The clearest difference is in-app purchases: Libre Light Sensor at none against Photone's 13. Libre Light Sensor also leads on review sentiment (82% vs 54%). Photone's advantage is ratings volume (4.9K vs 186) and device support (4 vs 1). On price, rating, update cadence and ads there is nothing between them.

Both are free to download. Photone sells 13 in-app purchases, starting at $5.49 per month. Libre Light Sensor asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.6 for Photone against 4.8 for Libre Light Sensor. That said, the two scores are not equally well evidenced: Photone has 4.9K ratings behind it against 186, so its average is the more settled of the two. Written reviews are what separate them: 54% of Photone's written reviews are positive against 82% of Libre Light Sensor's.

Photone ships an update every 3 weeks, Libre Light Sensor every 5 weeks. The most recent releases landed on October 26, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Photone | Libre Light Sensor |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (4.9K ratings)](https://appshunter.io/ios/app/photone-grow-light-meter/id1450079523/reviews) | **[4.8 (186 ratings)](https://appshunter.io/ios/app/libre-light-sensor/id1644439968/reviews)** |
| Number of ratings | **4.9K** | 186 |
| Positive reviews | 53.8% of reviews | **82.4% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 5 weeks |
| Monetization | Free with in-app purchases | **Free** |
| Size | 80 MB | 1 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Lightray Innovation GmbH](https://appshunter.io/developer/1031383431) | [John Harrington](https://appshunter.io/developer/1603002572) |

## What reviewers say

### Photone

[App page](https://appshunter.io/ios/app/photone-grow-light-meter/id1450079523)

This app acts as a professional-grade light meter for plants, measuring PAR, PPFD, DLI, and more using your device's camera. It helps optimize plant lighting by providing accurate readings and in-app guides, with optional advanced features available through purchase.

**Highlights:** Measure PAR, PPFD, DLI, lux, foot-candles, and kelvin, Research-grade accuracy using device camera, Pre-calibrated for specific devices, In-app guides and tools, Light source selection for various grow lights, Hands-free 'read aloud' function

**Features:** Apple Watch app

**In-app purchases (13)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Photone Pro (Monthly) | $5.49 | per month |
| Photone Pro (Yearly) | $29.49 | per year |
| MH lifetime unlock | $5.49 | one-time |
| HPS (Standard) lifetime unlock | $5.49 | one-time |
| HPS DE lifetime unlock | $5.49 | one-time |
| FL (Daylight) Lifetime Unlock | $5.49 | one-time |
| Sun Lifetime Unlock | $5.49 | one-time |
| LED Full Spec. lifetime unlock | $6.49 | one-time |
| LED (Red / Blue) Lifetime Unlock | $6.49 | one-time |
| LED (Blue / White) Lifetime Unlock | $6.49 | one-time |
| LED (Full Spectrum) Lifetime Unlock | $6.49 | one-time |
| LED (Full Spectrum + Red) Lifetime | $6.49 | one-time |
| Photone Pro Lifetime Unlock | $97.00 | one-time |

**What reviewers like**

- 🚀 Accurate readings
- 💡 Helpful for growing plants
- 👍 Easy to use
- 🚀 Saves money compared to expensive meters
- 👍 Useful for adjusting lighting

**What reviewers complain about**

- 🐛 Inconsistent readings
- 💰 Expensive in-app purchases
- 🔒 Requires additional equipment (diffuser) to work properly
- 🐛 Readings not accurate without calibration
- 🔒 Limited functionality in free version

**Reported bugs**

- Readings don't change with proximity
- Diffuser requirement not made clear upfront
- Purchased features not working as expected

**Requested features**

- Add calibration feature
- Expand supported light types in free version
- Improve accuracy across different devices
- Provide a one-time purchase option instead of subscription


### 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


## Frequently asked questions

### Is Photone free?

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

### Is Libre Light Sensor free?

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

### Which has better reviews, Photone or Libre Light Sensor?

Libre Light Sensor is rated higher. Photone averages 4.6 out of 5 from 4.9K ratings, while Libre Light Sensor averages 4.8 from 186 ratings.

### Do Photone or Libre Light Sensor have ads?

Neither Photone nor Libre Light Sensor shows ads.

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

Photone ships an update every 3 weeks, and Libre Light Sensor every 5 weeks. Most recently, Photone was updated on October 26, 2026 and Libre Light Sensor 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.*