Create network admin pages

I can’t find any documentation anywhere. I hope you can do this. I need the ability to register a network admin menu for my plugin. Basically the plugin stores settings for each site as a setting for the database. It would be extremely annoying if the admin of a large network had to go through the admin of each site to set the settings that they desired. I want to implement a network admin page where they can set the global settings that override all sites.

I would like to store the settings somewhere that can be retrieved by all sites like ‘get_network_option’ but that doesn’t appear to exist. I know I can just make it iterate over all of the blogs and change the settings one by one but I really want it to be isolated. Does wordpress make these APIs available?