Hi David,
Sorry for any confusion here. We do have a free plan, but it comes with a number of restrictions. We also have notifications in the plugin description and installation instruction about pricing and storage options. Still, your comment has shown that these notifications are not as clear as we thought they were. So we have added some additional info in the description, installation and FAQ sections. Hopefully, this will avoid any further confusion.
Also it’s worth knowing that our cloud viewer version supports reading from URLs, so you can use it like a local storage. Plus we will shortly have a WP plugin for locally hosted version of GroupDocs.Viewer for Java. With this plugin you will be able to host your files locally, without sending them to the GroupDocs Cloud API.
Thanks again for your comment,
Sergey Zhuravel
GroupDocs Support