All of these prototyping tools are great, but don't forget just paper prototyping. We've been doing a lot of AR paper prototyping (so lots of things on strings and hanging from the ceiling), and it's a pretty fun experience that really let's us define interactions.
That was a neat idea!
This is a great article. I follow the author on dribble and have always liked his animations. Glad to see he shared his thoughts with the design community.