Review for Provider for Google Calendar by Paulo Costa
Rated 5 out of 5 stars
For anyone saying that Lighting doesn't support Google Calendar anymore or that Provider for Google Calendar now doesn't work, see https://blog.mozilla.org/calendar/2013/09/google-is-changing-the-location-url-of-their-caldav-calendars/. The method described there for adding a writable Google Calendar totally works.
This review is for a previous version of the add-on (1.0.1).To create your own collections, you must have a Mozilla Add-ons account.