Depends on the type of app. React Native might be better for something resource heavy like a video app (we use it at Cameo for mobile, and regular react for web

Depends on the type of app. React Native might be better for something resource heavy like a video app (we use it at Cameo for mobile, and regular react for web), but if it is something like a todo list or email app, a wrapped webview would let you use the same codebase for web and mobile. For a backend, I'm partial to nodejs, it's nice having Javascript on both the frontend and backend. Something like Express or Restify is good for quickly setting up CRUD apps