Note of deprecation: This plugin will no longer receive updates in the future. I recommend using other plugins available.

Create posts from the relationship interface of the advanced custom fields plugin if they do not exist yet.

Install like any other plugin. Notice that the plugin only supports relationship fields with a single post type.

Install development dependencies via NPM: npm install

Use grunt-wp-deploy to deploy to WordPress.org:

grunt wp_deploy

The ACF - Add posts via relationship interface plugin is licensed under the GPL v2 or later.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2, as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

A copy of the license is included in the root of the plugin’s directory. The file is named LICENSE.

The plugin is licensed under the GPL v2 or later; however, if you opt to use third-party code that is not compatible with v2, then you may need to switch to using code that is GPL v3 compatible.

For reference, here's a discussion that covers the Apache 2.0 License used by Bootstrap.