Rated 1 out of 5 stars

FACT:
1. Anyone that says that this addon works flawlessly doesn't have to process invitations into there Google Calendar, which doesn't work, period.

2. Thunderbird Lightning is able to process Google Calendar requests out of the box, without the need of this addon, and is able to process invitations into Google Calendar, via Caldav. I urge users reading this to try Caldav first, which is the supported method.

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This add-on, while good intention, creates more confusion than it's worth, as people think that this add-on is required to access Google Calendar, and issues with this plugin and Caldav become intertwined creating more confusion on the forums and bug reporting. I urge the author to do the community a favor and remove this addon from the repository. If your going to donate, do so to the Mozilla foundation that manages Firefox and Thunderbird.

This review is for a previous version of the add-on (0.9).  This user has 2 previous reviews of this add-on.