When we are programming in NodeJS, is really annoying to restart the application just to see minor changes in the code, especially when you are making some web app with express. The quickest solution to this is nodemon.
Install
npm install -g nodemon
Usage
nodemon [your node app]
Example (express)
nodemon bin/www
While your application run through nodemon, every time that you change any file, he will watch the files in the directory in which was started, and if any files change, he will automatically restart your node application.
For more information visit: https://www.npmjs.com/package/nodemon