Add Babel as a dependency to your app's package.json file and define a start script

bebel-package.md

Add Babel as a dependency to your app's package.json file and define a start script:

{
  "dependencies": {
    "babel": "4.7.16"
  },
  "scripts": {
    "start": "./node_modules/.bin/babel-node ./app.js"
  }
}

Then you can simply execute the following command to run your app:

npm start

If you ever decide to stop using Babel (e.g. once Node.js supports all of the ES6/7 features), you can just update your package.json to the following:

{
  "dependencies": {},
  "scripts": {
    "start": "node ./app.js"
  }
}

One benefit of this is that the command to run your app remains the same, which helps if you are working with other developers.