Recently I updated my iPhone and even more recently over the past few days I keep seeing what I believe is the the icon that appears to return to to the previous app, however this happens in multiple apps even after I enter them normally through the homescreen. It flashes very quickly occasionally and I can never make out what it says, I also believe it is higher than the normal return to app icon. Is this a glitch? A virus? Did someone remote hack into my phone and that is the software that allows them do so showing?