If you want to host your static web apps, github page is certainly one of the best option. You can share both your code and demo in one place.

First create a react app in your local machine using the command npm init react-app app-name. Install gh-pages with npm install --save gh-pages and write the following lines in your package.json file.

{
    "homepage": "https://myusername.github.io/app-name",
    "name":"app-name",
    .
    .
  }
  .
  .
  .
  "scripts":{
    "predeploy": "npm run build",
    "deploy": "gh-pages -d build",
  }
  //Add and commit all changes.