I believe this has occurred even since the first version of iOS 9, and it still occurs on iOS 9.2 (Build 13C75) When closing apps out of the app switcher, the last remaining apps will cause the home screen card to start sliding into view. With the closure of one of these, the home screen will move too far, past the middle as you are sliding, but when you let go it snaps back into position. Happens on both my iPhone 6 and iPad mini 2. Kind of annoying looking. Has anyone else noticed? Please don't turn this into a "You aren't supposed to fully close all your apps, so this isn't even an issue" because yes, it is still an issue. It is instability of the UI, it should be able to handle any input you throw at it. And I usually don't even clear my apps, I just do every few days to just clean it out for my sanity while I'm actually using it, and to quit any potential stuck background processes.