Own Service in AngularJS

<!DOCTYPE html>
<html>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<body>
<div ng-app="myApp" ng-controller="myCtrl">
<p>The hexadecimal value of 2555 is:</p>
<h1>{{hex}}</h1>
</div>
<p>A custom service whith a method that converts a given number into a hexadecimal number.</p>
<script>
var app = angular.module('myApp', []);
app.service('hexafy', function() {
this.myFunc = function (x) {
return x.toString(16);
}
});
app.controller('myCtrl', function($scope, hexafy) {
$scope.hex = hexafy.myFunc(2555);
});
</script>
</body>
</html>