Is there a way to play with PWA-iness?

Hi @blake and @vimala

I’d like to see more of how Progressive Web Apps actually work for an end user. Do you know of any examples of (preferably Polymer) PWAs that are good? I know that the polymer project has a couple of PWA demo sites:

So these are good, nice and snappy. If I disconnect from the web, I can still keep on using them; some things work, some don’t. But it’s still a nice, coherent experience, they don’t just break like most sites do.

Is there a way to explore this further? How to ensure the whole site gets downloaded? Or can I pin it locally as an app? Are there any other sites you could suggest?