Review for gContactSync by PeterW
Rated 5 out of 5 stars
enables 2-way sync of contacts between Google Contacts and Thunderbird. Must have for Android users who want fully-featured offline email app on PC while using Gmail address book. Slow but works great. Replaced not-so-good 3rd party integration tools via Outlook.
This review is for a previous version of the add-on (3.0.0).To create your own collections, you must have a Mozilla Add-ons account.