Always I had a question, why framer for prototypes or what's the plus for use, apart for interact on my own mobile? Help to the developers? why not use after effects, Flinto or Principle ? Can any developers answer me? :)
I'm a designer not a developer, but to answer your question, some things can only be demonstrated in Framer/Origami. For instance, Facebook/Paper's tilt to pan through a photo. I suppose you could build a 3D phone in AE and show it that way, but it's not as powerful as being able to see it on device yourself
Also framer and origami use real logic that is very similar to what devs might use that can't be reproduced by other timeline based tools. After effects and principle "fake" that logic but framer is real
Framer uses coffeescript, which means that the logic of the animation is easily understandable by developers, or converted to usable code. Code also allows for more rapid prototyping - for example, you can create and populate a responsive grid in under a minute, meaning you can test more often and have a more efficient ideation workflow. Plus, there is an (almost) seamless integration with Sketch, making for a powerful design stack.
i love framer