Developer reply by Tomasz Lewoc
Rated 1 out of 5 stars
When will this Add On be made available for Seamonkey using Lightning?
This review is for a previous version of the add-on (0.3.1).It can already be installed in SM via a workaround. See here:
http://code.google.com/p/gt-tasks-sync/issues/detail?id=30
To create your own collections, you must have a Mozilla Add-ons account.