Classes relevant to handling the app switcher (also called "task switcher" or "multitasking switcher").
- SBAppSliderController - activate and toggle the app switcher.
- SBAppSwitcherModel - get the list of recently opened apps in the app switcher.
- SBMainSwitcherViewController - responsible for displaying the switcher on iOS 9+. Get the list of apps from -(NSArray *)recentAppLayouts;