With Publish to WordPress, you can publish your content on as many WordPress websites as you want.
Yes it does. Publish to WordPress authorize Google Docs to publish websites only with oAuth - a WordPress.com feature, so yes, it does work with all the WordPress.com websites too.
Yes it does. To Authorize your self-hosted site you need to have Jetpack Plugin installed on your site and make sure JSON API is enabled.
You just need to enable JSON API under settings and connect your site with WordPress.com.
Our add-in is absolutely free to use.
Plugmatter offers the best support and assistance to its users. For any issues or concerns, just shoot us an email at firstname.lastname@example.org and we'll get back to you at the earliest.