A format to store HDR (high dynamic range) content, referring to colorspace. The difference to non-HDR is huge on a good display and this is the one feature I want to see hands-on on these new iPhones..
I don’t have the answer to this, but giving your own app 5 stars seems totally reasonable and fair. It’s like voting, everyone has one vote, why on earth would you not vote yourself if you’re on the menu?