When I was a kid there were some shows on TV that had, across the bottom of the screen, the lyrics to the music being played, with a dark little ball bouncing off each word as it conveyer-belted away off the screen in a single line with the next ones incoming. As an adult I assume that was to help kids learn to associate the sounds with the letters and help them start to read.
I’ve got the little (smaller than yesterday!) bouncing–well, more like wobbling–dark ball at the bottom. But my eyeball just doesn’t have the built-in captions to match. Someone ought to get on that. I mean, this is Silicon Valley and all that, right?