Currently, this app is an adaptation of an older html page which i created a few years ago. It is based on Vladimir Agafonkin's suncalc.js library found at https://github.com/mourner/suncalc. I am currently using an older version of Chart.js https://github.com/chartjs/Chart.js.
I will try to update the manifest and cache url locations to work with url addressing such as rawgit so that it can be installed directly from this web page.
If you want to install this SunCalc PWA app, served up from my GitHub Pages, click this link in Chrome and you should be able to "Install" the app from the Chrome menu. This "Install" menu may only appear after having spent 30 seconds on the site.
I don't anticipate making too many changes to this repo, however I may perform minor cleanup and persisting of location data in local storage.