[Depricated - it's no longer free] Universal currency exchanger in Angular.js using freecurrencyconverterapi.com public API (ES5)

ngCurrencyExchange.js

app.service('CurrencyExchange', function($http, $q) {

  // using public API for currency exchange rates
  return function (from, rates) {
    var deferred = $q.defer();
    var base = from.toUpperCase();
    var currencies = [];

    if (typeof rates === 'string') {
      currencies = base + '_' + rates.toUpperCase();
    }
    else {
      rates.forEach(function(value){
        currencies.push(base + '_' + value.toUpperCase());
      });

      currencies = currencies.join(',');
    }

    $http.jsonp('http://www.freecurrencyconverterapi.com/api/v3/convert?q=' + currencies + '&compact=ultra&callback=JSON_CALLBACK')
      .success(function(data) {
        var prettyData = {
          base: base,
          rates: []
        };

        Object.keys(data).forEach(function(key){
          prettyData.rates.push({
            key: key.split('_')[1],
            value: data[key]
          });
        });

        deferred.resolve(prettyData);
      });

    return deferred.promise;
  };

});

Controller should look like this:

app.controller('CurrencyCtrl', function($scope, CurrencyExchange){

  CurrencyExchange('GEL', ['USD', 'GBP', 'EUR']).then(function(currencies){
    $scope.base = currencies.base;
    $scope.rates = currencies.rates;
  });

});

and the view:

ul.currency(ng-controller='CurrencyCtrl')
  li(ng-repeat="rate in rates")
    | 1 {{ base }} = {{ rate.value }} {{ rate.key }}