Not a huge deal, but I noticed my apps not closing when using the back button to back all the way out of apps. I'm a user who always hits the back button a million times to make sure apps are closed. I have noticed with the M8 that if I hold down the back button, I will still have apps opened. Is this a 8.1 thing or HTC? Has anyone else seen this? Doesn't seem to be effecting battery or anything, just curious.