For all of the people who still have questions about screen separation: I strongly suggest that you contact Apple. I had this issue, went to the Apple Store, and told them I suspected that it was due to a swollen battery. This girl seems to be a common enough issue, because they replaced it right away in store AT NO CHARGE. Of course I can't say that they would always handle the issue that way, but because of an issue with the battery in some iPhone 5s, there was a recall (Google iPhone battery recalls if you think this may be your issue, even if you already paid to fix it they might reimburse you), and in my case this qualified me for a free battery replacement anyway. The full phone replacement was a nice surprise.