ti.datastore.js

var $CONFIG = function(key, value) {
  if (arguments.length == 2) {
    if (value === null) {
      Ti.App.Properties.removeProperty(key);
    } else {
      Ti.App.Properties.setString(key, JSON.stringify(value));
    }
  } else if (arguments.length == 1) {
    var data = Ti.App.Properties.getString(key, false);
    return data && JSON.parse(data) || undefined;
  }
};

// Set config item
$CONFIG('user', { name: 'Josh', username: 'itspriddle' });

// Get config item
var current_user = $CONFIG('user');

// Delete config
$CONFIG('user', null);