The index page pops up normally. The top right hand button turns into "Done" after the page is fully loaded, works as expected.
However, it I remove the 3 cat photos, the top button stays at "Cancel" all the time.
I'm not sure what is the magic in the 3 cat photos? The only reason I would guess is that the page has to be above certain size in order for iOS to recognize a successful connection.
Tested on two iPhone 6 (6s) / iOS 9.3.4
Screenshot attached.