Hi David,
You may learn more about Jive Anywhere by reading about it here:
https://docs.jivesoftware.com/8.0_on_prem_int/sys_admin/jive.help.jiveanywhere/
In summary, Jive Anywhere allows you to collaborate directly from your web browser into your Jive environment. As per the system requirements, it does require the Extended APIs plugin, which is covered here:
Extended APIs Plugin
Let me know if you have any other questions on this.
Regards,
Jeph Yang