Awesome and nearly there! Rated 4 out of 5 stars

Using TB17 with Lightning 1.9 and things work great. Calendars load up and can be made read-only or two way sync. Haven't had any issues at all there!

Two major annoyances at the moment though:
-- Cannot categorize events to which you were invited (not author) - which makes no sense!
-- Cannot add attachments to an event

Any chance of those being remedied in the near future?

This review is for a previous version of the add-on (0.18).