Technically ANY dating site/app will allow this. Women can simply post this in the description box on their profile. Now I have never seen this happen on any profile I have ever seen on any dating site/app and probably for good reason. Most women simply feel that that is an invasion of privacy and don't want that information available to the public.
You could argue that a woman judging a man based on how tall he is or how much money he makes is just as superficial as a man judging a woman based on her boob size or how much she weighs, but that is just the world we live in. So for now no dating site/app that I have ever seen contains a built-in feature for boob size, even though they all contain a feature for how tall men are.