cc isn't available, so for that you'd need an roimagecanvas overlay transparency to stick on top, or create a custom roimagecanvas or roscreen for your springboard screen. It might be easier to add a "Play with closed caption" button for the user to select if they want closed captions visible and they are available for playback for the current item.
"destruk" wrote: Cool. What other stuff isn't documented that Roku can do?
Probably quite a bit. I know about that one, because I needed it for a couple of different channels I've worked on. There's also the 5.1 badge, but I don't recall how to display that one at the moment.