Review for Provider for Google Calendar by Jordan Grant
Rated 5 out of 5 stars
There may have been some issues in updating the app to Thunderbird 68.x.x, but they've been resolved. The app synchronized my calendar and tasks between Thunderbird and Google perfectly and instantly upon a refresh.
This review is for a previous version of the add-on (68.2.1).To create your own collections, you must have a Mozilla Add-ons account.