controller.js

var newTodo = todos.add(credentials).then(
                function(response) {
                    $scope.todos.push(response);
                    console.log(response);
                    console.log($scope.todos);
                    $scope.new_desc = "";
                }
            )

service.js

            add: function(credentials, savedSchema){
                var deferred = $q.defer();
                var newTodo = new Todo(credentials);
                newTodo.$save(
                    function(response){
                        deferred.resolve(response);
                    },
                    function(response){
                        deferred.reject(response);
                    }
                )
                console.log(newTodo)
                return deferred.promise;
            }