Re: iOS 9.2.1 App Switcher
It must be because "Reduce Motion" is enabled. Yes, I agree the app switcher was more fluid, but in 9.2.1 for those who have "Reduce Motion" enabled, like myself and probably you, it makes the app switching more on a 1-by-1 or "boxy" as you put. If you want the more fluid app switching experience you're going to have to go into Settings > General > Accessibility > Reduce Motion–OFF. But then again, if like myself, you don't like the animations it's going to bring those back, but at least the app switching will be that fluid motion that was once there pre-iOS 9.2.1. In sum, yes this is how Apple intended it to be, not sure how they thought this would be ideal for those who just didn't want/need the constant animations. If you really want that fluid app switching experience, you're going to have to put up with the iOS animations and disable "Reduce Motion."
Originally Posted by AugustVance
Try that, should work.