Test

HTML

<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.18/angular.js"></script>
<button ng-click="toggle = !toggle">{{toggleText}}</button>
<div class="box on" >{{divText}}</div>

JavaScript

var app = angular.module('my-app', [], function () {

})

app.controller('AppController', function ($scope) {
    $scope.toggle = true;
    
    $scope.$watch('toggle', function(){
        $scope.toggleText = $scope.toggle ? 'Click' : 'Cliked';
        $scope.divText = $scope.toggle ? 'Start' : 'Stop';
    })
})