Have you tried the soft reset? which is holding down the power button (on the iPhone 6 it's on the right side, other iPhones it's on top), until you see the slide to power off. Wait a few seconds and turn on again and try app. The other solution is…
Try this (not guaranteeing it will work, but it might):
Go to Settings>General>Background App Refresh and toggle it off. Close all apps including KKH, shut down device, wait 20 seconds, turn device back on. Open KKH app and see if it loads. …
I feel your frustration with those ads. As far as the boots, I believe they're still thigh high... Not that this matters, this whole event is testing A LOT OF NERVES. It really needs to be addressed.... Soon.
I think what glu meant was that you need a certain amount of space, apparently for the new update, which may be larger than it was before the update. Once you free up space, it should load fine. How you do that is going to Settings > General >…