Multi-window is one of the hottest and most unique aspects of OmniROM. The ability to use two applications at the same time is quite useful, and hopefully it will be included in nightly program soon. Multi-window is still described as work in progress, and XDA Senior Recognized Developer XpLoDWilD is working hard to make it as bug-free as possible.
Multi-window has already been implemented in various custom ROMs, but now this feature can be tried through the magic of Xposed Framework. XDA Forum Member LovewuChin created a module that lets users open two applications at the same time. Those applications can be used simultaneously in two work spaces, which can be switched to portrait or landscape mode. This module is still at a very early stage of development, but it’s quite functional. Thus you may notice some problems with specific apps, but most of them work just fine. App compatibility isn’t the only issue, though, as some application activities cannot be launched. Nevertheless, XMultiWindow is a great tool to try multi-window on anything with Xposed installed.
This Xposed module can be found in the original thread. So if you want to try to test multi-window and are running Xposed, don’t hesitate to give this a shot!_________