Thanks a lot for your work!
I installed this on DN4 and it works great (this should get implemented as a standard feature, imo).
I noticed a bug: When I edit the apps that actually show up in the sidebar, it takes the wrong app from the drawer. I chose for example tapatalk, hold my finger down on it and swipe it over to the sidebar and it gets changed to hangouts when I release it.
(I've read somewhere that this might have something to do with the number of apps in the multiwindow selection)
Here's my workaround for that: Open the sidebar, push "edit" and then the "reset" button. This way, you will move ALL apps into the sidebar. Now you simply have to move the ones you don't need back to the drawer.