Discourse was updated recently and after that update the browser showed an
Install button in the location bar that made it possible to install the website as an app. This was very similar to a feature that has existed on mobile devices for some time.
It was pretty cool. After install I could find that site / app in my applications, switch to it by app switching keyboard shortcut and so on. I don’t remember the name of this feature or if this is a progress web app but it’s nice.
This might be one of a few alternative solutions for some companies or individuals who want to continue to use Flash Player sites on or after 2020. You can leave FP disabled in your main browser but have a separate installed app that has it enabled.
Update: It is a progressive web app