People, please use a try/catch when feature testing for localStorage. If cookies are blocked for the domain, trying to access storage will throw a security exception. This exception will almost definitely hose whatever behavior you were trying to add. I see this on probably 60% of Show HN projects, but sometimes even on large sites.
Your core competency is testing web sites, right? I'd suggest making one of those 200 locations block cookies. You'll find 10x as many defects.
(edit And I'm assuming that localStorage is almost never really necessary for these sites, but that some bit of the framework tests for it without the developer even realizing it. So yes, I consider that a defect.)
But okay, I'll run it in another browser. Wow, it's a really cool WebGL visualization of global temperatures. And what is it using localStorage for? It sets one key called `runOnce` to `true`. I think that could be considered optional. Easy to fix, if they knew about it.
I tested in Chrome Win 10, with cookies disabled and privacy badger on and the capture page works fine. I want to debug the issue further to see whats preventing the locations from being displayed.
Have you tried clicking on the gear icon? That shows a list of locations.