CodeX allows you to preview the entire interface code right
within the Studio, for all platforms in real time. Import Sketch file to Supernova (we've gone to a great lengths to make sure your designs are imported properly), and all the production code is immediately created. When you do any change, when you prototype, the code changes as well.
I excitedly jumped in Supernova about a monthy or two ago, and really like the core concept. Except the React Native exports just were not up to scratch. They were really unusable. To top it off, I couldn't cancel my subscription. Everytime I attempted too, I'd get a little notification telling me "This feature will come next week." This happened for 2 weeks straight. I finally emailed them to cancel my subscription, they responded quickly and asked why I was cancelling. I gave them pretty good feedback, but never got an email back. I'm unsure how Supernova has matured over the last month, but I hope it's living up to expectations :)
Pros:Fast way to export sketch designs into working code.
Cons:React Native exports lack. A lot. Also you had to EMAIL THEM to cancel your subscription. Seriously.