AngularJS allows for maintenance of your chat apps. That is because when you need to add new features to your Angular application. It's a breeze wiith the upcoming Angular 2 framework the level of abstraction used to simplify your application development will make your life easy as the developer.
A Desktop based Chat app with node-webkit, Firebase and Angularjs
Tutorial : [Building a Chat App with node-webkit, Firebase, and AngularJS] https://github.com/vetripandi/chat-app-using-firebase-and-angularjs
Follow the Steps to run the Chat Application
Open command prompt
npm install
node app
Then open localhost:3000