Marked 2 as teleprompter, revisited - BrettTerpstra.com:
Once you have the theme, you can start prompting just by hitting the ‘s’ key in a Marked preview. That will start autoscroll at the slowest speed. Use left and right arrows to speed up/slow down the scroll speed. (You can also click and drag on the meter that appears in the lower left of the screen.) That’s all there is to it.
So this is amazing. Love it.