title: Flutter, preview of app and design plugin?
body: <p>Why flutter does not contain a preview of the app while we are programming it?</p>
  
  <p>Is there any design plugin to be able to drag and drop widgets like in android studio for android apps?</p>
  
  <p>It is difficult to build an interface from code without having a preview of the application.</p>
  
  <p>Thanks!!</p>