Speak Its Name is now available on Kobo and on the Nook. And that, so far as I know, is the lot. I’ve updated the page for the book with links to the purchase pages on all channels that I’m aware of.
If you have read the book and feel like leaving a review on any of those pages you feel would be appropriate, I would be delighted. The same goes for Goodreads, LibraryThing, BookCrossing or anything else of that ilk.