What is the best program for responsive design prototypes?

Question

Layouts and prototypes

Need a responsive design prototyping program like Justinmind ( www.justinmind.com/). To immediately see how it will look at different sizes.
Thank you.

Answer 1

Axure supports the creation of responsive layouts, and overall a nice tool.

Answer 2

I am an adherent of such an old-school method: to create a couple of document templates for Notepad ++, but everything is manual. For many, this is strange, unproductive, but it turned out that it was not for me.

Answer 3

I use printouts with the right adaptive grid and draw with a pencil. Or I make a prototype in Balsamiq. Then, when the idea is clear, I draw a layout in Photoshop on the same grid.