It doesn't look quite like I would expect for powdery mildew, check out these pictures of powdery mildew on apple from Google:
https://www.google.ca/search?q...
Honeycrisp is supposed to be susceptible to powdery mildew but Fuji is not from a couple of references I checked. The leaves are rather curled in your first picture though. If you don't see anything like the pictures of powdery mildew and you only have one leaf with a whitish end, maybe we need to look for something else. I wouldn't worry too much about the trees, they can have all sorts of problems that are resolvable or non-fatal.
