Rated 5 out of 5 stars

Best add-on ever used.
Using Open Google Calendar I'm able to include Google Calendar, Google Contacts, Google Keep, Google Drive, Google Photos, Google News & Google Search tabs whenever I open Thunderbird. Everthig is bi-directional & updates instantly across all my devices.
Don't really need a browser anymore.
Will be making a donation after this review

This review is for a previous version of the add-on (1.4).