angular-digest-measure.js

// load underscore from browser console
$.get('https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js');

// execute the following code
function getScopes(root) {
    var scopes = [];
    function traverse(scope) {
        scopes.push(scope);
        if (scope.$$nextSibling)
            traverse(scope.$$nextSibling);
        if (scope.$$childHead)
            traverse(scope.$$childHead);
    }
    traverse(root);
    return scopes;
}
var rootScope = angular.element(document.querySelectorAll("[ng-app]")).scope();
var scopes = getScopes(rootScope);
var watcherLists = scopes.map(function(s) { return s.$$watchers; });
_.uniq(_.flatten(watcherLists)).length;