LumenLeaf: PPFD Grow Light

LumenLeaf: PPFD Grow Light

PAR DLI Meter for Houseplants

2 ratings
3 reviews
Free

Details

Released
May 27, 2026
Updated
May 27, 2026

Features

LumenLeaf: PPFD Grow Light screenshot #1 for iPhone
LumenLeaf: PPFD Grow Light screenshot #2 for iPhone
LumenLeaf: PPFD Grow Light screenshot #3 for iPhone
LumenLeaf: PPFD Grow Light screenshot #4 for iPhone
LumenLeaf: PPFD Grow Light screenshot #5 for iPhone
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About

This app transforms your phone into a professional grow light meter. It measures PAR, DLI, illuminance, and color temperature to help you optimize plant growth. It's completely free, works offline, and requires no account or ads.

✓Measure PAR/PPFD
✓Measure DLI
✓Measure illuminance (lux)
✓Measure color temperature (Kelvin)
✓Supports various light sources
✓Offline functionality
✓No account required
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What's New in LumenLeaf

1.0

May 27, 2026

User reviews

Doesn’t work

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

Why Does a Light Meter Need My Microphone?

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.

全然動かない

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。

Response from developer

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。

Developer apps

FAQ

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.