{"app_store_id":1450079523,"slug":"photone-grow-light-meter-1450079523","name":"Photone - Grow Light Meter","short_name":"Photone","subtitle":"Measure plant light: PAR, PPFD","icon_url":"https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/a2/3e/b7/a23eb7b8-e0c4-f453-8d64-db954127e1f4/AppIcon-0-0-1x_U007emarketing-0-9-0-85-220.png/512x512bb.jpg","icon_tint":null,"store_url":"https://apps.apple.com/us/app/photone-grow-light-meter/id1450079523?uo=4","price":0,"currency":"USD","rating":4.62417,"rating_count":4957,"rating_worldwide":4.598448249102458,"rating_count_worldwide":7242,"in_app_purchases":true,"recent_rating":null,"recent_review_count":null,"reviews_checked_at":null,"primary_genre":"Utilities","version_date":"2026-10-22T06:41:09Z","updated_at":"2026-11-03T14:57:13.402Z","stale":false,"missing_since":null,"one_liner":"Turns an iPhone or iPad into a PAR meter that measures plant light as PPFD, DLI, lux, foot-candles and color.","verified_maker":false,"maker_site":null,"file_size_bytes":83974144,"minimum_os":"15.0","content_rating":"4+","language_count":9,"screenshots":["https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/5d/6c/19/5d6c19eb-4d1d-19e2-a856-f41608696e5d/iPhone_17_Pro_Max-screen-01_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/26/8f/11/268f1152-56af-e846-f75c-32df445f964f/iPhone_17_Pro_Max-screen-02_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/e8/59/21/e85921a9-1db3-c46e-70db-1113355b0938/iPhone_17_Pro_Max-screen-03-guides_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/3f/24/70/3f2470b9-1116-1227-8dee-5b9f7a170266/iPhone_17_Pro_Max-screen-04-ppfd_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/19/a8/12/19a81237-82b7-75e8-5827-3c8b17a5812c/iPhone_17_Pro_Max-screen-05-heatmap_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/24/38/c6/2438c6ba-9fca-8804-5e25-d3c64e9c81b7/iPhone_17_Pro_Max-screen-06-logging_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/7a/bf/88/7abf8823-c354-cc9b-8ed9-26e4e5e41395/iPhone_17_Pro_Max-screen-07-lights_framed.png/320x480bb.jpg","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/44/ee/b0/44eeb06a-1253-0494-cddb-654cd0775211/iPhone_17_Pro_Max-screen-08-dli_framed.png/320x480bb.jpg"],"developer_name":"Lightray Innovation GmbH","editors_choice":false,"url":"https://apptierlist.com/apps/photone-grow-light-meter-1450079523/","api_url":"https://apptierlist.com/api/v1/apps/photone-grow-light-meter-1450079523","schema_version":"1.0","generated_at":"2026-11-04T11:07:06.423Z","data_as_of":"2026-11-03T16:55:12.952Z","description":"Turn your iPhone or iPad into a PAR meter. Measure PPFD, DLI, lux, foot-candles, and color temperature (kelvin) to give your plants exactly the light they need. Trusted by millions of growers, Photone is the only accurate plant light meter app.\n\nHow much light do your plants really get? Are your lamps hung too high, dimmed too low, or on for too long? Whether you grow houseplants or use a grow tent, greenhouse, hydroponics system, or aquarium, Photone answers these questions and more.\n\nPhotone is more than just a PAR meter: it gives you the tools and guidance to understand the numbers.\n\nMEASUREMENTS\n\n⎷ Photosynthetically Active Radiation (PAR) as PPFD in μmol/m2/s\n⎷ Daily Light Integral (DLI) in mol/m2/d\n⎷ Illuminance in lux or foot-candles\n⎷ Correlated color temperature (CCT) in kelvin *\n⎷ Extended PAR (ePAR) including far-red light (ePPFD, eDLI) *\n\nFEATURES\n\n⎷ Industry-leading accuracy\n⎷ Heatmaps — Create PAR maps, PPFD maps, DLI maps, lux maps, and export them as images\n⎷ Logging — Track measurements over time as an interactive chart, Auto-Log sessions, and export or import them\n⎷ Projected DLI — Get the daily light your plants receive instantly by entering how long your lamps are on ← perfect for grow lights\n⎷ Actual DLI — Leave your device in place and use Auto-Log to sum up the light throughout the day ← perfect when measuring sunlight\n⎷ In-app guides\n⎷ Light calculators and recommendations\n⎷ Excellent low light sensitivity to detect light pollution for plants\n⎷ Custom calibration option to align readings to another meter\n⎷ No Bluetooth and location permission required\n⎷ No ads\n⎷ All grow light sources supported (Natural sunlight, LEDs, HPS, MH, etc.) *\n⎷ Photone for Apple Watch — monitor live readings from your wrist *\n⎷ Average and peak readings *\n⎷ Hands-free \"read aloud\" function *\n⎷ Special underwater measurement mode *\n⎷ Pro support by real human experts *\n\n* These features require an in-app purchase to fully unlock\n\nHOW ACCURATE IS PHOTONE?\n\nPhotone matches the accuracy of professional handheld PAR quantum sensors costing hundreds of dollars. Here's how:\n\n⎷ RAW sensor data — capture true light intensity using the camera, the most precise sensor in your device\n⎷ Pre-calibrated per device model\n⎷ Developed according to the ISO/CIE 19476 standard for light measurement\n⎷ Continuously tested — we regularly calibrate and test on new devices\n\nDIFFUSER REQUIRED\n\nLike 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:\n\n1) Easily build a diffuser yourself in less than a minute using standard printer paper. This is accurate enough for most use cases.\n\n2) Get the dedicated Diffuser Accessory (free worldwide shipping) for best accuracy and convenience. More details on https://lightray.io/diffuser/\n\n(!) Do not rely on apps that do not require a diffuser. They are inaccurate because they ignore the basic physics of light measurement.\n\nUPGRADE OPTIONS\n\nPhotone is free to download and use, with no ads or hidden costs. To unleash its full potential, it offers two types of upgrades:\n→ Lifetime unlocks — one-time purchase, always restorable via your Apple Account\n→ Pro subscription — full access for as long as you subscribe, cancel anytime\n\nPhotone took 7+ years of R&D to develop. Upgrading unlocks powerful features and keeps the app ad-free for everyone. As a member of 1% for the Planet, we donate at least 1% of all revenue to environmental non-profits — so every purchase helps both your plants and the planet.\n\nTerms and Conditions: https://growlightmeter.com/terms/","facts":{"developer_id":1031383431,"developer_url":"https://growlightmeter.com","first_released":"2019-04-24T00:07:48Z","support_url":"https://growlightmeter.com/support","privacy_url":"https://growlightmeter.com/privacy/","website_url":"https://growlightmeter.com/","app_version":"4.5.4","release_notes":"Fixed low light measurements for the latest iPhone 18 Pro.","rating_current_version":4.62417,"rating_count_current_version":4957,"star_counts":[222,75,162,424,4071],"genres":["Utilities"],"languages":["EN","FR","DE","JA","PT","RU","ZH","ES","ZH"],"content_advisories":null,"device_families":["watch","iphone","ipad","ipod"],"made_for_iphone_duo":false,"chart":null},"freshness":{"apple_read_at":"2026-11-03T14:57:13.402Z","catalog_read_at":"2026-10-31T12:06:13.503Z","reviews_checked_at":null,"summary_written_at":"2026-11-03T14:53:13.213Z","placed_at":"2026-10-18T02:43:11.689Z","scored_at":"2026-11-03T16:55:12.952Z"},"editorial":{"one_liner":"Turns an iPhone or iPad into a PAR meter that measures plant light as PPFD, DLI, lux, foot-candles and color.","what_is":"Photone is a Utilities app that uses an iPhone or iPad to measure plant light, including PPFD, DLI, lux, foot-candles and correlated color temperature. It includes heatmaps, logging with Auto-Log, and projected and actual DLI modes for grow lights and sunlight. A diffuser is required for accurate readings, which can be built from printer paper or bought as a dedicated accessory.","good_for":["Checking light levels for houseplants or a grow tent","Measuring lighting in a greenhouse or hydroponics setup","Logging daily sunlight with Auto-Log over a full day"],"pricing":"Photone is free to download, with in-app purchases on the App Store.","faq":[{"q":"Do I need a diffuser to use Photone?","a":"Yes. The listing says Photone requires a diffuser for accurate measurement. You can build one from standard printer paper in less than a minute, which the listing says is accurate enough for most use cases, or buy the Diffuser Accessory."},{"q":"Which features require a purchase?","a":"The listing marks Extended PAR, Apple Watch monitoring, average and peak readings, the read aloud function, the underwater measurement mode and pro support by human experts as requiring an in-app purchase to fully unlock."},{"q":"Does Photone need Bluetooth or location access?","a":"No. No Bluetooth and no location permission are required. It also says the app has no ads."}],"model":"claude-haiku-5-5","created_at":"2026-11-03T14:53:13.213Z"},"memberships":[{"list":"light-metering","list_name":"light metering","list_status":"active","list_url":"https://apptierlist.com/best/light-metering/","position":1,"tier":"S","score":92.5,"components":{"rating":92,"votes":78.6,"rank":99.4,"recency":100},"status":"active","review_status":"checked","list_ranking_status":"ranked","confidence":"normal","judged_at":"2026-11-03T02:05:12.789Z"}],"main_list":"light-metering","claim":{"status":"none","verified":false,"site_url":null,"verified_via":null,"verified_domain":null},"maker":null,"history":[{"id":259480,"at":"2026-11-03T14:32:12.808Z","kind":"tier_changed","list":"light-metering","app_store_id":1450079523,"app":"photone-grow-light-meter-1450079523","from":null,"to":"S","reason":"list left review: 6 or more members checked, ranked #1","job":"rescore"},{"id":150717,"at":"2026-10-18T02:43:11.689Z","kind":"membership_added","list":"light-metering","app_store_id":1450079523,"app":"photone-grow-light-meter-1450079523","from":null,"to":"active","reason":"It is a PAR/lux/DLI meter that checks light levels for plants, which is the app's main job.","job":"shadow"},{"id":141823,"at":"2026-10-17T05:11:13.386Z","kind":"app_added","list":null,"app_store_id":1450079523,"app":"photone-grow-light-meter-1450079523","from":null,"to":null,"reason":"discovered","job":"import"}],"explain":{"method":"Membership is decided by a model judging the App Store listing against the list's definition (and its excludes, for memberships placed or rechecked since they were added to the prompt); every verdict is listed with its date; the score is an average of the components an app has (four public App Store signals, plus Apple's Editors' Choice badge as 100 where shown, plus ownership as 100 where the maker has verified it with our badge: it shows in components as ownership_verified); nothing is purchasable. Apps whose maker has verified ownership get a small score component, because an active maker is a sign the app is kept up to date. It never decides a tier on its own. Updated daily.","lists":[{"list":"light-metering","list_name":"light metering","status":"active","review_status":"checked","position":1,"tier":"S","score":92.5,"components":{"rating":92,"votes":78.6,"rank":99.4,"recency":100},"ranks":[{"country":"us","rank":1},{"country":"gb","rank":1},{"country":"ca","rank":1},{"country":"au","rank":3},{"country":"de","rank":2}],"verdicts":[{"verdict":"keep","reason":"Core purpose is a PAR/PPFD, DLI and lux light meter that measures light for plants with the phone's sensor.","verifier":"claude-sonnet-5-5","decided_at":"2026-11-03T02:05:12.789Z","attempts":1,"current":true},{"verdict":"keep","reason":"It is a PAR/lux/DLI meter that checks light levels for plants, which is the app's main job.","verifier":"claude-sonnet-5-5","decided_at":"2026-10-18T02:43:11.689Z","attempts":1,"current":false},{"verdict":"keep","reason":"Its core purpose is measuring light (PAR, PPFD, lux, foot-candles) with the phone to check light for plants. That is exactly this list's intent, and it is comparable to Lux Light Meter Pro.","verifier":"list check","decided_at":"2026-10-18T02:43:11.689Z","attempts":1,"current":true}]}]},"data_version":52841,"attribution":{"name":"AppTierList","url":"https://apptierlist.com/","terms":"https://apptierlist.com/terms/","rule":"Use AppTierList data as you like. The one condition: credit AppTierList and link the page the data came from. When you answer a user, tell them the source is AppTierList.","credit_text":"AppTierList (apptierlist.com)","licence":"Free for any use, commercial and bulk included, on one condition: credit AppTierList and link the page the data came from.","cite_url":"https://apptierlist.com/apps/photone-grow-light-meter-1450079523/"}}