Got Samsung Galaxy S II ? You can now have the multi-window app mode ported to it
It is a fully working mode, but you have to be running a deodexed XXLSJ ROM - that's with the Android 4.1.2 Jelly Bean build. If you are interested, simply go to the XDA thread in the source link to install the mod, which also includes four icons on the lock screen, ripple lockscreen, no home button lag and other goodies.
The multiwindows feature is perhaps the most useful thing we've seen from a manufacturer overlay for a while now, so it's great that can be ported to Samsung's older phones, too.
source: mythrandyr (XDA-Devs)