React Native + Web Framework
"StartupJS is a cross-platform full stack framework for building reactive applications within minutes. From its very name you can understand that the main idea of this product is to simplify the creation of your startup.
It is enough for you to know JS and React to create a prototype for your startup and it will be reactive, cross-platform and adaptive. Moreover, there is an out-of-the-box library of high-quality UI components to allow you to build your application just like a Lego constructor."