<!DOCTYPE html>
<html>

<head>
  <script data-require="angular.js@1.5.8" data-semver="1.5.8" src="https://code.angularjs.org/1.5.8/angular.js"></script>
  <link rel="stylesheet" href="style.css" />
  <script src="script.js"></script>
</head>

<body>
  <h1>Creación de un servicio</h1>
  <div ng-app="reverse" ng-controller="reverseCtrl">
    <input type="text" ng-model="nombre" placeholder="Introduce un nombre" />
    <button ng-click="convertir()">Reverse</button>
    <p>El resultado es: {{reverso}}</p>
  </div>
</body>

</html>
// Code goes here
var app = angular.module("reverse", []);

app.service('alReves', function() {
  this.reves = function(frase) {
    return frase.split(" ").reverse().join(" ");
  }
});

app.controller("reverseCtrl", function ($scope,alReves){
  $scope.convertir = function (){
    $scope.reverso = alReves.reves($scope.nombre);
  };
});
/* Styles go here */

Creación de un servicio
Aplicar reverse a una String