Today, on February 19, 2019, book seven, Firstborn, has been released into the wild, dressed to go out in style in a cover by Jody Lee.
It is available in audiobook format from audible.com (apparently an audible.com exclusive, judging by the banner across the cover).
It is available in hardcover and as an ebook. (It is available as an ebook in Australia.)
I am both excited and nervous.