Developer reply by Leni Mayo
Rated 2 out of 5 stars
Using this resulted in the loss of many Google contacts. All of my Google contacts appeared in Thunderbird, but many of my contacts mysteriously disappeared on Google.
This review is for a previous version of the add-on (0.8.13.3).Have reached out to UncleBeard and asked him to file a bug report:
http://zindus.com/i/reporting-bugs
To create your own collections, you must have a Mozilla Add-ons account.