How can I include NPM modules in my app.js?

I'm just trying to learn Ionic right now. I'd like to use an NPM module, but I can't figure out how to import it into my app.js file. I have the default side-bar ionic setup right now. I looked into Browserify, but I can't figure out how to get that working with the Ionic / Angular (app.js) setup.

Do I need a backend? Do I need gulp? Or something else?

I'm really not sure what to do here. IE:

Node:

var ex = require('example'); // This is in ./npm_modules/example/
ex.doSomething({...});

Angular:

???