With version 3.7 WordPress introduced automatic updates. By default, these are on for maintenance and security releases only, but the underlying code is smart enough to support updates for plugins and themes. Here’s a simple plugin that will enable automatic updates for themes:
/** * Plugin Name: Enable Automatic Updates for Themes */ add_filter( 'auto_update_theme', '__return_true' );
And here’s one for plugins:
/** * Plugin Name: Enable Automatic Updates for Plugins */ add_filter( 'auto_update_plugin', '__return_true' );
Please note that these will work only if your host is configured to support automatic WordPress updates. You can learn more about configuring and debugging automatic background updates in the codex.