There's at least three - swipe up for home; swipe up halfway and hold for task switcher; swipe left for previous app. If you've turned on Reachability, there's also swipe down to activate that.
The edge gestures for switching apps aren’t new, they’ve been on the iPad for some time. The swipe up to app switch/go home is the only new gesture. Anyway my point stands: the home button was a massively overloaded bit of UI and no serious UX person would defend that.