Hi there!
Thanks for reaching out! I’d be happy to help with your question.
Our plugins do indeed work on WordPress Multisite installations. We have special multisite licenses for people who would like to use our plugins across many sites within a multisite installation, but our single licenses can also be used on a single site within the multisite.
To be clear though, there is no integration between the calendars on separate sites within a multisite. They still function as they would on a single install.
Hope that helps! Please let me know if you have any more questions about this.
Thanks,
Sky