CM/AOKP-Style Long-Press Back to Kill on TouchWiz ROMs
Custom Android ROMs are great because they often bring bonus features that let us make the most of our smartphones. While some may be perfectly happy with their current ROM, many will find themselves longing for more once they see it in another build.
If you find yourself bringing up a task manager app or going into settings to manually kill misbehaving apps, CyanogenMod and AOKP (as well as a few other ROMs) allow you to long-press the back button to kill the currently active app. Thanks to XDA Senior Member Mirko ddd, you can now get this feature right away on your device without having to flash a different ROM, provided it’s running a TouchWiz-based ROM.
The developer also offers a complete how-to guide for implementing this feature in any TouchWiz-based ROM, as well as a flashable zip file for salesale’s neat ROM. If you can’t implement it for your TouchWiz ROM yourself, the developer offers help with that as well. More information and the link to complete instructions can be found at the forum thread.