We've always been able to switch between running apps pretty easily, but iOS 7 beefed up the multitasking menu significantly by incorporating app previews in lieu of just icons.
Just double-tap the Home button and you'll see an assortment of cards displaying your most recently used apps with a snapshot of its last used screen. To force close one (or three), swipe the card(s) up. To scroll through them quicker, swipe the app icons instead of the cards.
While this is all great, it bothers me that so much screen real estate is wasted on my iPhone. Luckily, we can fix that with an easy-to-use... more