# LumenLeaf: Plant Light Meter — PPFD, Lux & PAR for Grow Tents

> Phone-based PAR/PPFD grow light meter for houseplants and indoor gardens. (iPhone/iPad app by lapnito.cz s.r.o..)

- Source: https://appshunter.io/ios/app/lumenleaf-plant-light-meter/id6771374329 (this page in markdown: same URL + `.md`)
- Developer: [lapnito.cz s.r.o.](https://appshunter.io/developer/1577358577)
- Category: Utilities, Lifestyle
- Price: Free
- Rating: 1.00/5 from 3 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.0 · 33 MB
- Languages: American English, Arabic, Czech, Danish, Dutch, French (France), German (Germany), Greek, Hindi, Indonesian and 13 more
- Released: 2026-05-27
- Data updated: 2026-11-13
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/lumenleaf-plant-light-meter/id6771374329/reviews.md

## What is LumenLeaf?

LumenLeaf turns your iPhone into a plant light meter for houseplants, grow tents, shelves, microgreens, herbs, hydroponics and greenhouses. It is free, works offline, and has no account, no ads and no subscription.

Measure PPFD (µmol/m²/s), Daily Light Integral (mol/m²/d), illuminance (lux or foot-candle) and colour temperature (Kelvin), then compare the result with what your plants need.

PLAN YOUR REAL GROWING SPACE
• Light Map: measure a grow tent or shelf point by point in a 3×3, 4×4 or 5×5 grid. You get a colour map, uniformity (min / avg) and concrete advice, for example "raise the lamp by about 10 cm".
• All-day DLI: log a windowsill or greenhouse over the whole day and get the real Daily Light Integral, compared with the needs of your plants. Passing clouds included.
• Places & plants: save spots like "Monstera by the window" with their plants and see at a glance whether each plant gets enough light.
• Your own calibration: calibrate against a known value, a PAR meter, the PPFD your lamp maker states, or a lux meter.

WORKS ON EVERY IPHONE
Put a sheet of white printer paper over the front camera and measure. The rear camera works too. The built-in guide shows how to set up the paper diffuser in about two minutes, so there is no hardware to buy. Camera permission only: no microphone, no location.

WHAT YOU CAN MEASURE
• PPFD in µmol/m²/s
• DLI in mol/m²/d with the photoperiod of your use case
• Lux and foot-candle
• Colour temperature in Kelvin (CCT)
• Per light source: sunlight, overcast sunlight, white LED 3000 / 4000 / 6500 K, HPS, metal halide, CMH, fluorescent T5 and T8, CFL, halogen
• Average, peak and minimum with Hold to Record

33 PLANT PRESETS
Monstera, fiddle leaf fig, snake plant, pothos, ZZ plant, calathea, succulents, cacti, orchids, microgreens, lettuce, tomato and pepper seedlings, basil, rosemary, mint and more, each with its target PPFD and DLI range. Add your own plant with a custom range at any time.

HONEST ABOUT ACCURACY
A phone camera is not a quantum sensor. On iPhones with a calibration profile LumenLeaf shows a calibrated camera reading; on other iPhones it uses a typical camera profile and marks the value as an estimate. Either way the app tells you which one you are looking at. Estimates are great for comparing spots and spotting changes. To make the absolute numbers your own, calibrate against a PAR meter or your lamp's stated PPFD. Readings are for horticultural guidance, not a laboratory instrument.

EVERYTHING IS FREE
• All measurements, light sources, plant presets, light maps and DLI logs
• Measurement history with CSV export
• No ads, no in-app purchases, no Pro tier
• No account, no sign-in
• Works completely offline
• 23 languages
• Report a problem straight from Settings: send a diagnostic report to support by e-mail

PRIVACY
LumenLeaf collects no data. No analytics, no tracking SDKs, no advertising IDs. Your readings, places and maps stay on your iPhone.

Made by lapnito.cz s.r.o.

## Key features

- Measure PAR/PPFD
- Measure DLI
- Measure illuminance (lux)
- Measure color temperature (Kelvin)
- Supports various light sources
- Offline functionality
- No account required

## Is LumenLeaf safe?

Not enough ratings yet to assess LumenLeaf.

## Is LumenLeaf legit?

LumenLeaf: Plant Light Meter appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for LumenLeaf is 70 out of 100 points across 7 verification signals from App Store and developer data.

## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/lumenleaf-plant-light-meter/id6771374329/reviews.md

### 1/5 — 不能使用

*2026-11-05*

糟糕的体验

### 1/5 — Doesn’t work

*2026-10-05*

Doesn’t actually seem to work at all. Could not get a reading above 0 no matter what I did.

### 1/5 — Why Does a Light Meter Need My Microphone?

*2026-09-26*

A plant light/PPFD meter requiring microphone access feels very questionable. Camera access makes sense, but microphone access does not. When I denied microphone permission, the app stopped working completely.

That’s a major privacy concern for me. Users should be aware before installing.

### 1/5 — 全然動かない

*2026-07-14*

ダウンロードしたけど、何も動かない。利用不可という表示が出るだけ。何かを設定する機能もない。

**Developer response:** レビューありがとうございます。アプリが正常に動作せず、「利用不可」と表示されるとのことで申し訳ありません。設定項目も含めて問題を確認し、次回のアップデートで修正いたします。

## Frequently asked questions about LumenLeaf

### What can LumenLeaf measure?

LumenLeaf can measure Photosynthetically Active Radiation (PAR/PPFD), Daily Light Integral (DLI), illuminance in lux and foot-candle, and color temperature in Kelvin (CCT). It also distinguishes readings from sunlight, white LED, HPS, CMH, fluorescent, and mixed light sources.

### How accurate is LumenLeaf?

LumenLeaf is transparent about its accuracy, distinguishing between camera-based readings and Ambient Light Sensor (ALS) estimates. If your phone lacks a calibration profile, it will inform you rather than silently reducing accuracy.

### Does LumenLeaf require any special hardware?

No physical hardware is required. LumenLeaf provides an interactive walkthrough to help you build a simple printer-paper diffuser in under 2 minutes, which is needed for accurate measurements.

### Is LumenLeaf available in my language?

Yes, LumenLeaf is available in 20 languages from its launch, making it accessible to a global user base.

### What devices does LumenLeaf support?

LumenLeaf is supported on iPhone and iPod devices. It utilizes the phone's rear camera in RAW mode when available for enhanced accuracy.

### How often is LumenLeaf updated?

LumenLeaf was last updated on May 27, 2026, with version 1.0. This indicates a recent release, and users can expect future updates based on developer activity.

### What is the age rating for LumenLeaf?

LumenLeaf has an age rating of 4+, making it suitable for a wide range of users, including younger individuals interested in plant care.

### Does LumenLeaf collect user data?

No, LumenLeaf prioritizes user privacy. It has zero data collection, no analytics SDK, and no advertising IDs, ensuring your usage remains private.

## Version history (last 2 releases)

### 2.0 — 2026-11-11

LumenLeaf 2.0
• Works on every iPhone: measure with the front camera and a sheet of paper
• No microphone permission any more
• More accurate readings with exposure correction, plus your own calibration against a known value
• Light Map: measure your grow tent or shelf in a grid and get uniformity and lamp-height advice
• All-day DLI logging for windowsills and greenhouses
• Places & plants: save spots like "Monstera by the window" and see if each plant gets enough light
• Report a problem straight from the app
Still free and offline. No ads, no account, no data collected.

### 1.0 — 2026-05-27

No release notes.

## Apps similar to LumenLeaf

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [GrowPAR](https://appshunter.io/ios/app/growpar/id6762544264) | — | Free | Utilities |
| [Light Meter: Plant Lux & PPFD](https://appshunter.io/ios/app/light-meter-plant-lux-and-ppfd/id6772273072) | — | Free | Utilities |
| [Par Meter : PPFD Monitor](https://appshunter.io/ios/app/par-meter-ppfd-monitor/id6757111998) | 2.5 (2) | Free | Utilities |
| [Grow Calc: Plant Light Meter](https://appshunter.io/ios/app/grow-calc-plant-light-meter/id6751297015) | — | Free | Utilities |
| [LUX METER- Lux,Fc,PPFD](https://appshunter.io/ios/app/lux-meter-luxfcppfd/id6780143255) | — | Free | Utilities |
| [LightMeter Pro: Lux Meter](https://appshunter.io/ios/app/lightmeter-pro-lux-meter/id6759503979) | — | Free | Utilities |

## More apps by lapnito.cz s.r.o.

- [FuelFare: Trip Cost Calculator](https://appshunter.io/ios/app/fuelfare-trip-cost-calculator/id6450358923)
- [NoiseLedger: Decibel Meter](https://appshunter.io/ios/app/noiseledger-decibel-meter/id6450401003)
- [Pragueguides](https://appshunter.io/ios/app/pragueguides/id6480465076)
- [QR Reader & Code Generator](https://appshunter.io/ios/app/qr-reader-and-code-generator/id6757708053)
- [Scan to PDF: Sign & Redact](https://appshunter.io/ios/app/scan-to-pdf-sign-and-redact/id6759046751)
- [Color Picker: Photo & RAL](https://appshunter.io/ios/app/color-picker-photo-and-ral/id6759371237)

All apps by lapnito.cz s.r.o.: https://appshunter.io/developer/1577358577

## Related topics

[grow light](https://appshunter.io/ios/topics/grow-light) · [ppld](https://appshunter.io/ios/topics/ppld) · [ppfd free](https://appshunter.io/ios/topics/ppfd-free) · [ppfd](https://appshunter.io/ios/topics/ppfd)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-11-13.*