Originally Posted by RobertJSawyer
Jgaiser, even before the update, about half the time, the justification switch had no effect, sadly. I don't know why Kindle/Amazon makes this so difficult. Kobo devices allow full justification to be turned off reliably (and without a hack), and the iBooks app on iOS devices allow it, too (although the switch to turn it off is hidden in the Settings app).
It depends on the book. If the book creator has "hardwired" full justification into the book, eg with:
then it's going to stay fully justified regardless of what option you choose.
It's never a good idea to hardwire such settings into books, but unfortunately many book creators do.