With the new Samsung Galaxy Note II, there's a new Multi Window mode that allows users to run two different apps simultaneously on the tablet's screen. This feature works with Samsung and Google apps like Gmail, YouTube, Chrome and Talk.
With the list of the functioning applications being short, XDA forum member goddamnit has created a new mod that allows the Multi Window feature to be used with any application on your Samsung Galaxy Note 2.
Once you've rooted the phone, you'll have to flash the mod in recovery mode, which should allow you to add any application to the Multi Window mode. Make sure you flash the mod that's specifically made for your ROM's version (LJ1, LJ3, and LJ7).
You can listen about the new mod in the video below, starting at 1:39.