I've been using Principle and Flinto for Mac over the last few days, and even though I might be jumping here, I've come to the following conclusion:
Principle is really great for doing single view animations with interplay between elements in the same view (i.e. Drivers). Flinto is really great for doing transitions between multiple views (i.e. Transition Designer).
Now this might be a case of me not doing it right, but as soon as I try it the other way around (simple multi-view transitioning in Principle, or single view animations in Flinto) things tend to get really, really messy.
If I could just have one tool that did both these things (yes, yes, Framer.js and to some extent Pixate) as intuitively as they currently stand alone, I'll give you all the money.
What are your initial thoughts?