The WSBK app is completely useless, filled with bugs, and crashes constantly. Even if it worked, there isn't much on it. It has been like that for many years. I don't understand why they don't fix it. I've written to them tons of times.
The GP app is better, but still nearly useless compared to the website (which is also gone to crap the last few years with giant pictures creating endless scrolling, but sharing very little actual info without a LOT of clicking around...something that used to be taboo in design).
I'm not sure if either is on Start TV apps. My new Roku Ultra came today. I'll poke around once I have the courage to set aside a week for "quick setup!"
Let us know if you find anything!
A few hints:
To nav WSBK easily, you may want to choose the "news" link. You'll still get a site designed by kids w/1/30th of the data you want without scrolling...but you'll get news.
If you select videos, they've "helped" again and separated them by their topic choices (not user/your filtering choices). Good luck. I hate it. You can see highlights "easily."
My favorite is to select Calendar, then Round, then Schedule. From there a normal human can look at any given day, then any given event (race/practice/etc.) for any group and view results (text, thank the Gods), or watch the races directly from links on that page. If you set your initial link to calendar instead of the home site, you won't see results, which they love to post so that the race-watching is immediately ruined for everyone who was looking at that screen.
I start on calendar for MotoGP also, but the interface was designed by preteen teletubbies. If you want to see more than one or part of one thing...you're going to have carpal tunnel from scrolling and clicking 72 layers in.
As I'm fond of saying...Humans, the worst.