---
title: "Photone - Grow Light Meter - Reviews, Revenue and Downloads in United States | Apple App Store"
description: "Take the guesswork out of plant lighting with Photone, the most accurate plant light meter app. Measure PAR, PPFD, DLI, lux, foot-candles, and color temperature (kelvin) directly with your phone or ta"
---

# Photone - Grow Light Meter — United States
> Perfectly light your plants!

![Photone App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/c6/12/6f/c6126f8e-1286-54a9-b5c1-c81d0b7b2aea/AppIcon-0-0-1x_U007emarketing-0-9-0-85-220.png/400x400bb.png)

**Developer:** [Lightray Innovation](https://apptail.io/developer/lightray-innovation-MKJ) (Germany)
**Category:** Utilities
**Rating:** 4.6/5 (4,843 ratings)
**Price:** Free
**Bundle ID:** com.dominikmaglia.korona
**Store:** Apple App Store
**Country:** United States
**Version:** 4.5.3 (released 2026-09-30)
**Original Release:** 2019-04-24

**App Store Link:** [Download on Apple App Store](https://apps.apple.com/us/app/app/id1450079523)
**AppTail Page:** [https://apptail.io/app/photone-grow-light-meter-JQq/united-states](https://apptail.io/app/photone-grow-light-meter-JQq/united-states)

## Photone Description
Take the guesswork out of plant lighting with Photone, the most accurate plant light meter app. Measure PAR, PPFD, DLI, lux, foot-candles, and color temperature (kelvin) directly with your phone or tablet.

To measure light with research-grade accuracy, Photone uses the most precise sensor in your device: the camera. Its unique measurement algorithm works directly with the RAW camera sensor data to capture true light intensity. This allows Photone to rival professional handheld PAR meters in accuracy and go even further by helping you interpret the numbers with in-app guides, tools, and additional features.

MEASUREMENTS

⎷ Photosynthetically Active Radiation (PAR) as PPFD in µmol/m²/s
⎷ Daily Light Integral (DLI) in mol/m²/d
⎷ Illuminance in lux or foot-candles
⎷ Light color temperature in kelvin *
⎷ Extended PAR (ePAR) including far-red light (ePPFD, eDLI) *

FEATURES

⎷ Industry-leading accuracy, comparable to professional PAR quantum sensors
⎷ Pre-calibrated for your specific device
⎷ Excellent low light sensitivity to detect light pollution for plants
⎷ No ads
⎷ No Bluetooth and location permission required
⎷ In-app guides
⎷ Light source selection for every type of grow light (LED, HPS, CMH, etc.) *
⎷ Average and peak readings *
⎷ Plant light calculator
⎷ Hands-free “read aloud” function *
⎷ Special underwater measurement mode *
⎷ Custom calibration option to align readings to another meter
⎷ Premium support for advanced grow questions *

* These features require an in-app purchase to fully unlock

DIFFUSER REQUIRED

Like every real light meter, Photone requires a diffuser to measure accurately. A diffuser scatters incoming light evenly on the sensor and prevents hotspots. While it may sound complex, the solution is surprisingly easy. You have two options:

1) Easily build a diffuser yourself in less than a minute using standard printer paper. This is accurate enough for most use cases.

2) Get the dedicated Diffuser Accessory (free worldwide shipping) for best accuracy and convenience. More details on 

(!) Do not rely on apps that do not require a diffuser. They are inaccurate because they ignore the basic physics of light measurement.

UPGRADE OPTIONS

Photone is free to download and use with all basic features without any ads or hidden costs. To unleash its full potential, Photone offers two types of upgrades:
→ Lifetime unlocks — one-time purchase, always restorable via your Apple Account
→ Pro subscription — full access for as long as you subscribe, cancel anytime

Photone took more than 5 years of R&D to develop. Upgrading not only unlocks powerful features, but also supports future development and keeps the app ad-free for everyone. As a member of 1% for the Planet, we donate at least one percent of all revenue to environmental non-profits — so every purchase helps both your plants and the planet.

ACCURACY

Accuracy is not an afterthought — Apps developed by Lightray Innovation are developed according to the ISO/CIE 19476 standard. Thanks to RAW image processing and a default calibration per device model they’re able to match the performance of high quality traditional hardware light meters. To ensure quality we rigorously test our apps regularly on upcoming devices.


DOWNLOAD FOR FREE. TRUSTED BY MILLIONS.

Optimized for plant growers and indoor gardeners – whether you're growing in a grow tent, greenhouse, hydroponics system, an aquarium, or are just looking for the best quantum meter app for your LED grow lights, Photone has got you covered.


Terms and Conditions: 

## Photone Screenshots
- [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/bd/72/5b/bd725b8b-8a8b-6d3c-7956-290914b26d97/Watch-01.png/422x514.png)
- [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/f3/52/f1/f352f103-722d-1f57-6e08-2cc2ddf9134c/Watch-02.png/422x514.png)
- [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/3c/29/82/3c29825d-fc35-58eb-6050-3d090a2f6e04/Watch-03.png/422x514.png)
- [Screenshot 4](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/1d/c9/52/1dc95245-ae26-98ca-922b-f8dc34e3e301/Watch-04.png/422x514.png)
- [Screenshot 5](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/04/18/9c/04189c65-a37b-29f1-ab6f-bb60f724888e/Watch-05.png/422x514.png)

## Photone Rating Breakdown in United States
- 5 stars: 3,977 (82%)
- 4 stars: 416 (9%)
- 3 stars: 159 (3%)
- 2 stars: 72 (1%)
- 1 stars: 219 (5%)

## Photone Reviews in United States

### *---- "Pay wall for LED"
This app is misleading you. Unless you need to go back in time when people used fluorescent lights to grow plants this app is useless in the free format.
-- SnapDragon999, 2025-08-29

### *---- "Clueless"
No explanation on how to use
-- I inform, 2025-08-11

### ***** "The best"
The best app for light measuring (Period).
-- rogue4177, 2025-08-03

### ***** "Don’t wait just buy it!"
Don’t hesitate should have bought this sooner!
-- Gas main, 2025-07-20

### *---- "Frightful app"
You download a “free” app. Then it makes you pay so you can assess intensity of sunlight which is the point of a light meter. Fine, I pay. Then I’ve got to pay for a diffuser???? I deleted app. This fool is not parting with any more money.
-- floofel, 2025-07-17

### *---- "Highly inaccurate"
The app is off by over 400 ppfd when compared to an actual PAR meter. The diffuser I spent an additional $30 on is wildly off the mark. I get far more accurate results using a piece of printer paper. Support doesn’t help. They just blame it on the user, refuse to offer any solutions, and pretend like it didn’t happen. I emailed them and never got anywhere. They basically said “We don’t know what the problem is. Never seen that before. Sorry and good luck!”

Avoid this app. They are not serious about helping cultivators.
-- cbipskabip, 2025-07-03

### *---- "Bait and switch"
I don’t appreciate bait and switch. There is no limited free trial without signing up for a subscription. Congratulations you have convinced me to buy a dedicated device instead.
-- DesignatedDriver, 2025-06-27

### *---- "Doesn’t work and feel scammed"
Very displeased to only find out AFTER purchasing that it won't function unless you also get a diffuser, which they attempt to sell you. On top of that it doesn't work anyway. multiple readings came out  different, and when I turned my light up, the reading went down.
-- Ed It Or Else, 2025-06-23

### *---- "Bad pay walls need to end."
Seriously just want to know if my plants are getting enough light, but nah - gotta pay $6 just to do that. Half the app is locked behind that stupid paywall.
-- Peopled Out, 2025-06-22

### *---- "Nope"
You don’t follow international trade laws boo! Why don’t you give me your right to jury trial in exchange for ALL of your data! This is the way of Thieves. Crooks. Charlatans. Not that I’m saying that’s what you are, of course, just pointing out something I’m positive you probably overlooked with your lawyers and law school and all of that
-- @3(9.1'fqptytho, 2025-06-03

[View all Photone reviews and detailed analytics on AppTail](https://app.apptail.io/signup?utm_campaign=ai-crawl&utm_content=reviews)

## Photone In-App Purchases
| Item | Price |
|------|-------|
| LED Full Spec. lifetime unlock | $6.49 |
| Photone Pro (monthly) | $5.49 |
| Photone Pro (yearly) | $29.49 |
| Sun lifetime unlock | $5.49 |
| LED Red / Blue lifetime unlock | $6.49 |
| LED B/W lifetime unlock | $6.49 |
| LED Full + Red lifetime unlock | $6.49 |
| FL daylight lifetime unlock | $5.49 |
| HPS DE lifetime unlock | $5.49 |
| Photone Pro Lifetime Unlock | $79.99 |


## Photone Discovered Keywords
- photo light
- metering tools
- exposure meter
- iso
- light meter
- lightmeter
- lumu light meter
- grow journal
- lumen
- lux light meter

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- [Grow with Jane - Grow journal](https://apptail.io/app/grow-with-jane-grow-journal-gmbc/united-states)
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## Photone Available In
- [United States](https://apptail.io/app/photone-grow-light-meter-JQq/united-states)
- [Thailand](https://apptail.io/app/photone-grow-light-meter-JQq/thailand)
- [Germany](https://apptail.io/app/photone-grow-light-meter-JQq/germany)
- [Canada](https://apptail.io/app/photone-grow-light-meter-JQq/canada)
- [Brazil](https://apptail.io/app/photone-grow-light-meter-JQq/brazil)
- [United Kingdom](https://apptail.io/app/photone-grow-light-meter-JQq/united-kingdom)
- [Australia](https://apptail.io/app/photone-grow-light-meter-JQq/australia)
- [China](https://apptail.io/app/photone-grow-light-meter-JQq/china)
- [France](https://apptail.io/app/photone-grow-light-meter-JQq/france)
- [Taiwan](https://apptail.io/app/photone-grow-light-meter-JQq/taiwan)
- [Switzerland](https://apptail.io/app/photone-grow-light-meter-JQq/switzerland)
- [Japan](https://apptail.io/app/photone-grow-light-meter-JQq/japan)
- [Italy](https://apptail.io/app/photone-grow-light-meter-JQq/italy)
- [Argentina](https://apptail.io/app/photone-grow-light-meter-JQq/argentina)
- [Russia](https://apptail.io/app/photone-grow-light-meter-JQq/russia)
- [Spain](https://apptail.io/app/photone-grow-light-meter-JQq/spain)
- [Netherlands](https://apptail.io/app/photone-grow-light-meter-JQq/netherlands)
- [South Korea](https://apptail.io/app/photone-grow-light-meter-JQq/south-korea)
- [New Zealand](https://apptail.io/app/photone-grow-light-meter-JQq/new-zealand)
- [Sweden](https://apptail.io/app/photone-grow-light-meter-JQq/sweden)
- [South Africa](https://apptail.io/app/photone-grow-light-meter-JQq/south-africa)
- [Austria](https://apptail.io/app/photone-grow-light-meter-JQq/austria)
- [Mexico](https://apptail.io/app/photone-grow-light-meter-JQq/mexico)
- [Türkiye](https://apptail.io/app/photone-grow-light-meter-JQq/turkey)
- [Finland](https://apptail.io/app/photone-grow-light-meter-JQq/finland)
- [Hong Kong SAR China](https://apptail.io/app/photone-grow-light-meter-JQq/hong-kong)
- [Singapore](https://apptail.io/app/photone-grow-light-meter-JQq/singapore)
- [Philippines](https://apptail.io/app/photone-grow-light-meter-JQq/philippines)
- [Chile](https://apptail.io/app/photone-grow-light-meter-JQq/chile)
- [Belgium](https://apptail.io/app/photone-grow-light-meter-JQq/belgium)
- [Colombia](https://apptail.io/app/photone-grow-light-meter-JQq/colombia)
- [Vietnam](https://apptail.io/app/photone-grow-light-meter-JQq/vietnam)
- [Czechia](https://apptail.io/app/photone-grow-light-meter-JQq/czechia)
- [Malta](https://apptail.io/app/photone-grow-light-meter-JQq/malta)
- [Poland](https://apptail.io/app/photone-grow-light-meter-JQq/poland)
- [Ukraine](https://apptail.io/app/photone-grow-light-meter-JQq/ukraine)
- [India](https://apptail.io/app/photone-grow-light-meter-JQq/india)
- [Hungary](https://apptail.io/app/photone-grow-light-meter-JQq/hungary)
- [Norway](https://apptail.io/app/photone-grow-light-meter-JQq/norway)
- [Denmark](https://apptail.io/app/photone-grow-light-meter-JQq/denmark)
- [Malaysia](https://apptail.io/app/photone-grow-light-meter-JQq/malaysia)
- [Israel](https://apptail.io/app/photone-grow-light-meter-JQq/israel)
- [Saudi Arabia](https://apptail.io/app/photone-grow-light-meter-JQq/saudi-arabia)
- [Portugal](https://apptail.io/app/photone-grow-light-meter-JQq/portugal)
- [Bulgaria](https://apptail.io/app/photone-grow-light-meter-JQq/bulgaria)
- [Indonesia](https://apptail.io/app/photone-grow-light-meter-JQq/indonesia)
- [Ireland](https://apptail.io/app/photone-grow-light-meter-JQq/ireland)
- [Romania](https://apptail.io/app/photone-grow-light-meter-JQq/romania)
- [Greece](https://apptail.io/app/photone-grow-light-meter-JQq/greece)
- [Slovakia](https://apptail.io/app/photone-grow-light-meter-JQq/slovakia)
- [Croatia](https://apptail.io/app/photone-grow-light-meter-JQq/croatia)
- [Lithuania](https://apptail.io/app/photone-grow-light-meter-JQq/lithuania)
- [Peru](https://apptail.io/app/photone-grow-light-meter-JQq/peru)
- [Slovenia](https://apptail.io/app/photone-grow-light-meter-JQq/slovenia)
- [Uruguay](https://apptail.io/app/photone-grow-light-meter-JQq/uruguay)
- [Egypt](https://apptail.io/app/photone-grow-light-meter-JQq/egypt)
- [Kazakhstan](https://apptail.io/app/photone-grow-light-meter-JQq/kazakhstan)
- [Estonia](https://apptail.io/app/photone-grow-light-meter-JQq/estonia)
- [Ecuador](https://apptail.io/app/photone-grow-light-meter-JQq/ecuador)
- [Luxembourg](https://apptail.io/app/photone-grow-light-meter-JQq/luxembourg)
- [Latvia](https://apptail.io/app/photone-grow-light-meter-JQq/latvia)
- [Qatar](https://apptail.io/app/photone-grow-light-meter-JQq/qatar)
- [United Arab Emirates](https://apptail.io/app/photone-grow-light-meter-JQq/united-arab-emirates)
- [Mauritius](https://apptail.io/app/photone-grow-light-meter-JQq/mauritius)
- [Armenia](https://apptail.io/app/photone-grow-light-meter-JQq/armenia)
- [Belarus](https://apptail.io/app/photone-grow-light-meter-JQq/belarus)
- [Dominican Republic](https://apptail.io/app/photone-grow-light-meter-JQq/dominican-republic)
- [Kuwait](https://apptail.io/app/photone-grow-light-meter-JQq/kuwait)
- [Bahrain](https://apptail.io/app/photone-grow-light-meter-JQq/bahrain)
- [Tunisia](https://apptail.io/app/photone-grow-light-meter-JQq/tunisia)
- [Panama](https://apptail.io/app/photone-grow-light-meter-JQq/panama)
- [Sri Lanka](https://apptail.io/app/photone-grow-light-meter-JQq/sri-lanka)
- [Iceland](https://apptail.io/app/photone-grow-light-meter-JQq/iceland)
- [Macao SAR China](https://apptail.io/app/photone-grow-light-meter-JQq/macau)
- [Algeria](https://apptail.io/app/photone-grow-light-meter-JQq/algeria)
- [Nigeria](https://apptail.io/app/photone-grow-light-meter-JQq/nigeria)
- [Angola](https://apptail.io/app/photone-grow-light-meter-JQq/angola)
- [Pakistan](https://apptail.io/app/photone-grow-light-meter-JQq/pakistan)
- [North Macedonia](https://apptail.io/app/photone-grow-light-meter-JQq/north-macedonia)
- [Madagascar](https://apptail.io/app/photone-grow-light-meter-JQq/madagascar)
- [Paraguay](https://apptail.io/app/photone-grow-light-meter-JQq/paraguay)
- [Jordan](https://apptail.io/app/photone-grow-light-meter-JQq/jordan)
- [Ghana](https://apptail.io/app/photone-grow-light-meter-JQq/ghana)
- [Brunei](https://apptail.io/app/photone-grow-light-meter-JQq/brunei)
- [Bermuda](https://apptail.io/app/photone-grow-light-meter-JQq/bermuda)
- [Uzbekistan](https://apptail.io/app/photone-grow-light-meter-JQq/uzbekistan)
- [Grenada](https://apptail.io/app/photone-grow-light-meter-JQq/grenada)
- [Senegal](https://apptail.io/app/photone-grow-light-meter-JQq/senegal)
- [Suriname](https://apptail.io/app/photone-grow-light-meter-JQq/suriname)
- [Cyprus](https://apptail.io/app/photone-grow-light-meter-JQq/cyprus)
- [Oman](https://apptail.io/app/photone-grow-light-meter-JQq/oman)
- [Belize](https://apptail.io/app/photone-grow-light-meter-JQq/belize)
- [Nepal](https://apptail.io/app/photone-grow-light-meter-JQq/nepal)
- [Azerbaijan](https://apptail.io/app/photone-grow-light-meter-JQq/azerbaijan)
- [Mali](https://apptail.io/app/photone-grow-light-meter-JQq/mali)
- [Namibia](https://apptail.io/app/photone-grow-light-meter-JQq/namibia)
- [Jamaica](https://apptail.io/app/photone-grow-light-meter-JQq/jamaica)
- [Lebanon](https://apptail.io/app/photone-grow-light-meter-JQq/lebanon)
- [Barbados](https://apptail.io/app/photone-grow-light-meter-JQq/barbados)
- [Uganda](https://apptail.io/app/photone-grow-light-meter-JQq/uganda)

---

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