Sunlit

Terms of Use

Last updated 2 September 2026.

What you are getting

Sunlit is an iPhone app that computes the position of the sun, the moon and the galactic centre of the Milky Way. It is free to install and free to use for today's date at your current location. A single non consumable in app purchase, Sunlit Pro, unlocks any date, saved places, the moon, the Milky Way, annual paths, the measured horizon, eclipses, widgets, notifications and export. There is no subscription and there is no second product.

The purchase

Sunlit Pro is bought once and belongs to your Apple Account. It restores on any device signed in to that account, through Restore Purchases on the paywall or in Settings. Payment, refunds and family sharing are handled by Apple under the terms of the App Store, not by us. Apple's standard licence applies in addition to this page and can be read at apple.com/legal.

What the numbers are, and are not

Sunlit computes solar position with the NREL Solar Position Algorithm and lunar position with a truncated ELP-2000/82 series. Those figures are accurate to the tolerances stated in the App Store listing.

The UV index and the irradiance figures are clear sky models, not measurements. They estimate what a cloudless sky would deliver. Cloud is not modelled. Do not use them as a substitute for sun protection advice, for a UV meter, or for any decision where being wrong would harm you.

Rise, set and twilight times assume a flat horizon unless you have traced your own skyline in the app. Nothing here is suitable for navigation, aviation, maritime use, or any purpose where a life depends on the number.

Your data

There is no account and no analytics of ours. Saved places, a traced horizon and your settings are written inside the app on your device and never leave it. The free version shows advertising, delivered by Google's ad kit, which loads only after you have agreed to it and which Sunlit Pro removes. The privacy policy sets all of that out in detail, including the provider, the legal basis and how to withdraw your consent.

This website

These pages set no cookies. The pages that describe the app use Vercel Web Analytics, a cookieless measurement service of the hosting provider. It sets no identifier and builds no profile of you. It counts page views, and it counts clicks on the App Store button together with the place that button occupies on the page and the path of the page it sat on. Nothing in it is evaluated per person, and none of it is passed on to anybody else. The site is hosted by Vercel Inc., 440 N Barranca Avenue #4133, Covina, CA 91723, USA, whose privacy policy is at vercel.com/legal/privacy-policy.

Liability

Sunlit is provided as it is, without warranty of any kind. To the extent the law allows, we are not liable for any loss arising from use of the app or reliance on its figures. Nothing here limits any right you have as a consumer that cannot be limited by agreement, and in Germany that includes liability for intent and gross negligence, and for injury to life, body or health.

Changes

If these terms change, the date at the top of this page changes with them.

Contact

Levin Schwab, Paulinenstrasse 1/2, 71263 Weil der Stadt, Germany.
levin.schwab@gmx.de