The attached .zip file is to be used with custom recovery and flashes OmniSwitch.apk (extracted from OmniROM) to /system/priv-app, the app needs to be in this location for the kill apps function to work. You can also copy the attached apk to system/priv-app, you will also need to set the permissions to rw-r--r--, do not install it. If you're interested in the source code, you can find it here.
This thread was created with maxwen's permission.
Edit: I have changed both files, from what I saw with the tests I did, both methods work now. Thanks to ultimahwhat for the new apk and to OrglCe for his zip creator.
Let me know if there are any problems.
Edit: If you have any permission problems, it should be fixed after using lucky patcher to remove signature verification on your phone, as always, this is at own risk.
21/05/2014: Update to version 1.1. New feature has been added. Signature differs so you can't use the apk to update the old version.
26/05/2014: Version 1.1 should work correctly now.