OK, with the release of a new prototyping tool every week and the arrival of both Flinto and Principle, what is the best prototyping tool? I have tried Framer, Pixate, Principle, After Effects, and Flinto. Yet, I'm undecided on the one (if any) to purchase. I can see it becoming an helpful/useful addition to my workflow.
What features would you want from the perfect tool?
What if the prototyping tool was included in Sketch? What if they generated full HTML + CSS + JS or Swift or Java code? (That'd be nifty) What if they were all free instead of paying $99?