Chromecast built-in on U1

Hi everyone.

I recently bought the U1 (my first Android media player). When the screensaver comes on, I see it says "Chromecast built-in". But, for the life of me, I can't get it working or showing up in any of my cast menus.

Can someone confirm if this is indeed supported on the U1? If so, how did you set it up?

Thanks.