How do you get that tool?

posted to: Arcs of Motion I

That tool you use to deform the cube. I might have missed something in an earlier lesson. I'm trying to be better with being consistent with my learning my lessons here. But in the next lesson too you also have that deformation tool following the cube. I think how to make or even download already made tools like that would be very useful. Do you have a lesson addressing this question directly?  I hope so. And thank you for your help!