The application “Spot” lets you highlight specific zones of your page by choosing :
The rectangular/square or circular/elliptical shape
Maintaining of the proportions
The display mode (by a mouse click or persistent)
A preview of the shape
A transparency of the mask
As for the other tools, “Sport” is available in the “Applications” of the library.
Also note that you can use the “Mask” tool to progressively display the content of a screen.