SunAlly

I’m No ability to enter Theraputic light time. I do mine from 4am to 5 am which the app considers ineffective sun exposure time for vitamin D synthesis and with no ability to enter it as Theraputic. Vitamin D tracking is useless. Also no ability for sunlight tracking from Apple Watch. HRV does not update either.

The app won’t measure outdoor activity and I can’t customize activity outside when it doesn’t read correctly

I downloaded about 10 different sun apps, and this is the best one for automatically tracking sun exposure using time in daylight on an Apple Watch. It calculates how much vitamin d you’re getting from the sun based on this metric. Right now, the only improvement I could see would be having the uv index be written to apple health when it notices that you are in the sun. Waiting for that feature, but enjoying the app.