Jeff Ellingson, Googles product manager for Gmail posted this a few days ago:
For many years, we’ve supported two open protocols for accessing Gmail and Calendar from mobile apps
and devices: IMAP for email and CalDAV for calendar. These protocols, combined with the options to access Gmail, Calendar, and Contacts with your desktop or mobile browser and via native apps on iOS and Android, help ensure you have a great experience regardless of the device you use.
Starting today, we’re adding CardDAV – an open protocol for contacts – to that list. CardDAV enables 3rd party clients, like the iOS contacts app, to sync your Google contacts. By supporting IMAP, CalDAV, and CardDAV together, we’re making it possible for 3rd parties to build a seamless Google Account sync experience.
To sync your Google Contacts on iOS using CardDAV, please follow these instructions in our Gmail Help Center.
This is a great upgrade and we at Phoenix SEO company are happy to see Google continue development in this area.