FAQ

This plugin uses the WP-cron to schedule events which synchronise the data. WP-cron is the system built into WordPress to handle the scheduling of time-based tasks and to simulate a system-cron. However, WP-cron is not always reliable on low traffic sites because it needs traffic to call the scheduled events. See: Understanding WP-Cron Scheduling.

If your site does not get visits regularly and you really want the tasks to run on time – take a look at: Hooking WP-Cron into the System Task Scheduler.

No, you only need to insert the license at the site which is your monitor.