OK, thanks.
I was able to "complete" my channel project: a Google Photos viewer, allowing me to browse & view the photos & videos uploaded automatically by my phone to Google Photos. Basically, it's just a registration screen, a posterGrid scene to browse albums, another posterGrid to browse photos & videos thumbs, and a videoPlayer for videos, or a Poster for photos.
There's a lot of things I do server-side, like rotating the images based on their EXIF orientation data, because I couldn't find how to do that in the Roku SDK, or I thought it was just easier to do server-side. But otherwise, I think it works good enough.
I'll probably publish it on Github after playing with it for a while.
Thanks again for the pointers.
