There seems to be an app switching concept craze going on at the moment with iOS, but I think it's a good thing, it means someone's trying to make something better. The current app switching in iOS is not ideal and many others will agree.
Sentry, an aspiring UX designer, has come up with a new concept that completely eradicates the need to press any button to switch to another app. His ideal method would be to simply swipe up from the bottom left of the screen to reveal app icons and their current state. Just like how you swipe down to access notifications, he wants to apply the same method to app switching - you wouldn't double press a button to open up notifications now would you.
A concept like this can easily be made into a Cydia tweak so we may even see it available in Cydia at some point.