App Store slow on iOS 8.4 and 8.4.1

Why App Store opens so late in iOS 8.4. And I updated my iPhone few days ago it's Same also. App Store opens so late. But what is the reason ???. Before I had iPhone 4 with ios 7.1.2 it was really good App Store. But even now I have iPhone 5 but App Store is so slow more than iPhone 4 with iOS 7.1.2.... Please help me