I just cast from whichever app I was using. For instance, I have the HBO app on my phone, I open it, find what I want to watch, and cast from there. I think the change is that you can cast your screen now whereas previously, I only was able to use screensharing with my Samsung TV.
What was the situation before? No Chromecast or just a different implementation?
You can cast from any app that supports it. I think the article talks about screen mirroring with chromecast.
I just cast from whichever app I was using. For instance, I have the HBO app on my phone, I open it, find what I want to watch, and cast from there. I think the change is that you can cast your screen now whereas previously, I only was able to use screensharing with my Samsung TV.