Yes, you can cast your favorite streamers and Twitchers to any device you'd like with Chromecast. A lot of people don't seem to realize that Twitch works just fine with Google's little streaming dongles. This way if you don't have a big computer you can still enjoy all those Fortnite battles.
Basically, you can use your phone and a $35 streaming Chromecast dongle to watch your favorite Twitch Player (go Ninja) on your big screen TV in the living room. Take Twitch with you anywhere.