whole_func_string: function (app, callback) {
      var cozyLight = require('./cozy-light');
      var config = configHelpers.getConfig();
      logger.info('Uninstalling ' + app + '...');
      if (config.apps[app] === undefined) {
        logger.error(app + ' is not installed.');
        nodeHelpers.invoke(callback, true);
      } else {
        var module = config.apps[app].name;
        npmHelpers.uninstall(module, function removeAppFromConfig (err) {
          if (err) {
            logger.raw(err);
            logger.error('npm did not uninstall ' + app + ' correctly.');
            nodeHelpers.invoke(callback, err);
          } else {
            logger.info(app + ' successfully uninstalled.');
            configHelpers.watcher.one(callback);
            configHelpers.removeApp(app);
          }
        });
      }
    }
func_code_string: function (app, callback) {
      var cozyLight = require('./cozy-light');
      var config = configHelpers.getConfig();
      logger.info('Uninstalling ' + app + '...');
      if (config.apps[app] === undefined) {
        logger.error(app + ' is not installed.');
        nodeHelpers.invoke(callback, true);
      } else {
        var module = config.apps[app].name;
        npmHelpers.uninstall(module, function removeAppFromConfig (err) {
          if (err) {
            logger.raw(err);
            logger.error('npm did not uninstall ' + app + ' correctly.');
            nodeHelpers.invoke(callback, err);
          } else {
            logger.info(app + ' successfully uninstalled.');
            configHelpers.watcher.one(callback);
            configHelpers.removeApp(app);
          }
        });
      }
    }
func_documentation_string: Remove app from config and its source from node module folder.
  
  @param {String} app App to uninstall.
  @param {Function} callback Termination.