Apologies for the lack of details - this is just our landing page and of course will be built out further.
In answer to your questions: yep, it supports Thunderbird. Yep, it supports CardDAV. In terms of syncing with your Google Contacts, I'm not 100% sure what you mean but you can import all of your Google Contacts and keep them synced up through Columns (if that's not what you meant please let me know!)
iOS and WP8 both cannot pull in custom phone number fields from Google Contacts.
For example, some people I have a mobile number, but then I also have a "Google Voice" number with them. When pulling that contact in to my iPad, it loses the Google Voice number.
Does Columns keep the custom free text fields? I assume iOS and WP8 don't because they both pull in Google's contacts using Outlook.
Apologies for the lack of details - this is just our landing page and of course will be built out further.
In answer to your questions: yep, it supports Thunderbird. Yep, it supports CardDAV. In terms of syncing with your Google Contacts, I'm not 100% sure what you mean but you can import all of your Google Contacts and keep them synced up through Columns (if that's not what you meant please let me know!)
Hope that helps and thank you for your time.