Get list of WP Updates Across Sites

Is there a way to query a WP site to see the number of updates currently available? I’m not really looking for a list of the actual updates, just the number. This would be the total number of Plugin/Theme/Core updates, like it is listed in the WP admin menu.

I manage multiple WP sites across multiple servers and would like an easier way of knowing when updates are available, rather than checking them individually.

You can use the http://managewp.com/ to maage all your sites from one dashboard.

From site

ManageWP helps you manage all your WordPress sites from one location,
keeping them updated and secure.