With iOS 7, we have been given a whole new App Switcher interface that gives you application preview cards that you can swipe through, or swipe up on to close.
If you want to change the display-consuming cards to a grid view, as shown above, then check out a new jailbreak tweak called GridSwitcher
by iOS developer tom-go.
The new grid view packs more application preview cards into the display, making it easier for you to multi-task. You can still swipe up on application preview cards, even in grid view, to close them from the App Switcher, but you have the benefit of seeing more applications at once.
GridSwitcher works on iPhone, iPod touch, and iPad, as long as they're running iOS 7. On the iPhone and iPod touch, the tweak gives you a 2x2 grid in the App Switcher, as shown above, but for the larger canvas on the iPad, the tweak will give you a 3x3 grid in the App Switcher.
Currently, the tweak has no options to configure, but in the future the developer may let the user configure the grid sizes for iPhone, iPod touch, and iPad users that want to pack even more application preview cards into a smaller space. If you want to give GridSwitcher a try, it's available in Cydia's BigBoss repository for $1.50.
iPhone 5 running iOS 7.0.6