I believe it's also only for the newer camera module found in the 6s/6s+, SE and iPad Pro 9.7".
Like the post above says. It will mostly be for 3rd party (which they can't update to do yet until iOS is released.) It may come to the stock app (I could see it as an iPhone 7 thing with its rumoured larger sensor *phyisically larger, not larger in the sense of megapixels.)
It also adds the capability to edit RAW with the addition.