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Show HN: I built a daily sunlight tracker

(www.lumehealth.io)
45 points vickipow | 4 comments | 26 Jun 25 23:28 UTC | HN request time: 0.832s | source

I kept trying to explain how important outdoor light is and how most people aren’t getting enough. Eventually I figured that showing is more effective than telling.

So we built a free app that uses your Apple Watch or iPhone to automatically track your light exposure throughout the day.

It tells you if you’re getting enough, shows you how consistent you are, and rewards habits that support hormone balance.

It's in beta on TestFlight, let me know what you think!

1. coolandsmartrr ◴[30 Jun 25 14:35 UTC] No.44423867[source]▶
Looks cool!

A couple questions:

(1) Are you supposed to join the waitlist to use this ("Get Early Access"), or can you just start using via TestFlight ("Download Today")? I see two different links on this page.

(2) How does this app measure the amount of light received by the Apple Watch? Does the Watch have such sensors and expose such APIs?

replies(1): >>44425300 #
2. vickipow ◴[30 Jun 25 16:42 UTC] No.44425300[source]▶
Thanks (1) You can join the waitlist for our hormone tracking device, the app is available for download today on TestFlight. Eventually the app will be used to show you the connection to your hormone balance (like cortisol etc.) and your light exposure. They are very tightly linked! (2) there is a light sensor in the display of the Apple Watch that automatically tracks it. It works ~80% of the time, but struggles if you have a big jacket
replies(1): >>44425558 #
3. dylan604 ◴[30 Jun 25 17:02 UTC] No.44425558[source]▶
Most people have their phone in a pocket or purse or similar while outdoors. Wouldn't this require the phone to be out and exposed to light in order to work correctly? So not only are you trying to get people to change habits of getting outside, you're also requiring they change habits with the devices as well. Good luck with that, and I mean that with more sincerity than snark but not no snark.
replies(1): >>44426868 #
4. vickipow ◴[30 Jun 25 19:20 UTC] No.44426868{3}[source]▶
The light sensor is in the Apple Watch display (behind the screen) it's what it uses to adjust the screen brightness. So if it's exposed to the sun it will count it automatically