public function getNavigation() {
        $plugins = Admin::getModels();
        $navigation = array();

        foreach ($plugins as $plugin) {
            $models = array();

            foreach ($plugin['models'] as $model) {
                if ($model['installed']) {
                    $models[Inflector::humanize($model['group'])][] = $model;
                }
            }

            $navigation[$plugin['title']] = $models;
        }

        return $navigation;
    }