What are some alternatives?
When comparing Expo Sketch and Marvel for Sketch, you can also consider the following products
React Navigation - Description will go into a meta tag in <head />
Fluid for Sketch - Sketch plugin to make your responsive designs more efficient
Webcodesk - A low-code rapid development tool for React Web applications
Anima - Create High-Fidelity Prototypes in Sketch
Native Navigation - Application and Data, Mobile, and Cross-Platform Mobile Tools
Webflow Flexbox UI Builder - Build flexible, responsive layouts — without writing code