Effect of Image updates as User scrolls page.

Hi
I am looking for an effect where an image appears on the page – stays in the same place as the user scrolls but a new overlay is added at certain points.

Best displayed here:
https://web.archive.org/web/20160326052657/https://astonclub.com.au/index.html

So the phone appears and as the user scrolls the instructions appear on the right and the appropriate screen overlay changes.

Is there a plugin for this effect or how would I start trying to replicate that effect.

Ernie