Recently Google announced will be discontinuing Google Sync for consumers effective January 30, 2013, this will affect those iOS devices users who use Google Sync with Mail, Calendar and Contacts to their mobile devices. If you are using Microsoft Exchange ActiveSync synchronize your Google Apps mail, contacts, and calendars on iPhone or iPad and worry about disappearance of Google Sync unable to access all of your data then can use CalDAV and CardDav services provided by Google.
Google Sync applies only to those with Google paid apps (Business, Government or Education) account after January 30, 2013. Google Sync uses Microsoft Exchange ActiveSync to let users synchronize their Google Apps mail, contacts, and calendars to their mobile devices, the users can one time add contacts, calendars or mail for synchronization. CalDAV is Google calender sync client whereby CardDav is Google contacts client allow users access and sync contacts on server, so users need to be set up separately.
CardDav And CalDav Set Up
First your Gmail account already set up on your iOS devices and turn on for mails and calenders option.
Then go to 「Setting」 > 「Mail, Contacts, Calenders」 > 「Add account」, then select 「Other」.
Select 「Add CardDav Account」 or 「Add CalDav Account」 that preferred, now you have to go through a slightly more complicated configuration process because you’ll be using different protocols.
Enter details as below
Username: Gmail account
Password: Gmail password
Description: Google (You can enter what you like)
Tab on 「Next」 to continue. If a pop up window with message 「Cannot connect using SSL」 appeared, tab on 「continue」 to process it.
Your Google calender events and Google contacts will sync across all iOS devices after few minutes.