React.js with Node.js Rest API

Should I include my Reactjs app in the same application as my REST API?

I am new to Reactjs. I have built a few standalone Node REST APIs. I am building a React app, an Android app and an iOS app (so the REST API needs to service all three applications). I was wondering what convention dictates when building the Node API.

There are 2 options as I see it...

1) I could build one large application that encompasses the REST API and React App. This app would service all the API calls from the mobile apps and react/web app. It would also serve all the views aka HTML, CSS, etc..

OR

2) I could build two smaller apps. One would serve the React app with the view templates with a separate (lighter) Node server. The second app would not hold any views. It just work as a JSON API to serve all three apps.