Terms of use
Last updated 28 September 2026
The short version. Buy it from Apple, use it on your devices, do not take it apart and sell it. It tells you where the sun will be; it does not know about the weather, the snow, or whether the trail is safe.
1. The agreement
Ridgelight is made by Sam Harper ("we"). By using the app you agree to these terms and to Apple's Licensed Application End User License Agreement, which applies to every app sold through the App Store. Where the two disagree, Apple's terms win.
2. What you get
A personal, non-transferable licence to use the app on devices you own or control, for as long as Apple's terms allow. The purchase is one time; there is no subscription and nothing expires.
3. What you may not do
- Reverse engineer, decompile or disassemble the app, except where the law says you may
- Rent, lease, resell or redistribute it
- Remove or obscure any notice in it
4. Accuracy, and the limits of it
The astronomical calculations use the standard published algorithms and are accurate to well under a minute. The terrain is another matter: it comes from open elevation surveys sampled on a grid, and it does not know about trees, buildings, or anything built since the survey. A first light time is as good as the ground data underneath it.
Do not use this app as a safety tool. It does not know the weather, the visibility, the snowpack, the tide, or whether the road is open. Plan for the dark, tell someone where you are going, and carry a light.
5. Data from others
Elevation data comes from public sources including SRTM and NED, distributed through AWS Terrain Tiles. Map imagery comes from Apple Maps and is governed by Apple's terms. We make no claim of ownership over either.
6. No warranty
The app is provided "as is", without warranty of any kind, to the fullest extent the law allows. It may contain errors. It may be unavailable.
7. Limitation of liability
To the fullest extent permitted by law, our total liability for any claim relating to the app is limited to what you paid for it. We are not liable for indirect or consequential loss, including a missed shot, a wasted trip or a cold morning.
8. Refunds
Apple handles all purchases and therefore all refunds: reportaproblem.apple.com.
9. Changes
These terms may change as the app changes. The date at the top says when they last did.
10. Governing law
New York, United States, without regard to its conflict of law rules.
11. Contact
Sam Harper — ericrosenbaum77@gmail.com