I want to add backend module written node.js, How do I do? #71

Thank you for offering this useful source.
I am new in Angular JS full.
I want to show real time cryptocurrency data updating every 5 seconds, where do I add the back-end file or code?
Now there is 2 files to be connected.

callAPI.js

var IR = require('./backend/index');
var publicClient = new IR();
// get ticker for BTC-USD
publicClient.getMarketSummary("Xbt", "Usd", console.log);

myAPIs.js

var util = require('../node_modules/util'),
_ = require('../node_modules/underscore'),
request = require('../node_modules/request'),
//crypto = require('../node_modules/crypto'),
cheerio = require('../node_modules/cheerio'),
VError = require('../node_modules/verror');
IndependentReserve.prototype.getMarketSummary = function getMarketSummary(primaryCurrencyCode, secondaryCurrencyCode, callback)
{
this.getRequest('getMarketSummary', callback, {
primaryCurrencyCode: primaryCurrencyCode,
secondaryCurrencyCode: secondaryCurrencyCode}
);
//Get data from the exchange's offical API. 'https://api.independentreserve.com'
};

After all my questions are following :

1. Where do I add callAPI.js or its contents?
   Do I need to something to gruntfile.js?

2. How do I connect the result data to view controller?

3. How do I implement auto data refresh every 5 seconds?

Regards.
Antonio.