Ever since iOS 9 showed up, my App Store app has been acting funny. Before upgrading my phone (due to certain reports, I waited until 9.1 arrived) the App Store would often display "Cannot Connect to App Store" on every screen but the update page. After upgrading.... Same thing.
Today, the page is just blank and it's been that way for a bit. But Quartz reported on a trick worth trying: "Tap on the tab bar of any item 10 times." They report that tapping on any item in the App Store navigation bar should clear the app's cache and get it working again. Further, this is apparently a fix for other Apple App's with caches, like iTunes and Watch's included app.
Why not allow users to clear caches in the app's settings page, which is clearly the most obvious place to put the tweak?