I have just heard of Google no longer allowing new users into the Google Sync service (Google's ActiveSync). They have announced that they now support CardDAV along with their already existing IMAP and CalDAV services and expect users to use those protocols for Google Contacts, GMail, and Google Calendar. CardDAV is a protocol that allows one to synchronize contacts, IMAP is an e-mail protocol to access e-mail, and CalDAV is a protocol for synchronizing calendar entries.
I was recently trying to help someone be able to sync multiple calendars to their iPhone and referenced the article I wrote earlier about synchronizing multiple Google calendars but found that the link at the bottom of the article no longer pointed to the right Google page to do so.
These two events have brought me to write this article to provide the links to choose which calendars are synchronized to an iOS device. I did some research and found that there are two different pages based on how you have your device set up to load the calendar. Below, I have provided the two links.
To update your calendar selection using Google Sync, open up your phone browser to the link provided below. Sign in with your Google account and it will provide a list of devices that have accessed your calendar. Since I've had several iPhones, it shows multiple items with the name "iPhone". Select the device for which you want to sync calendars and then it will provide a list of calendars associated with your account.
Google Sync link: https://m.google.com/sync/settings/
To update your calendar selection using Google's CalDAV protocol, open up your browser to the link provided below. Sign in to your account and immediately it will list the calendars to sync or unsync (check or uncheck) with any device using CalDAV.
Google's CalDAV link: https://www.google.com/calendar/syncselect
Check mark all of the ones you want to see. When done, select "save" at the bottom to save your settings. Congratulations! You have successfully updated your Google calendar settings for your device. You can now open up your calendar app and see the change in calendars.