Note: XMultiWindow is an Xposed Module and requires Xposed Framework to work. It also requires your phone to be rooted.
Installation
Assuming that you have already installed Xposed Installer on your device, you can download “XMultiWindow” from the “Download” section (Alternatively, you can download the app here).
After the download, activate it in the “Modules” section.
Usage
The usage is very simple. First, run the XMultiWindow app and click the “Sidebar Settings,” followed by “Sidebar App Settings.”
From here, you can tap the “ADD” button at the top right hand corner to add the apps that you want to run in split view mode. Note that you have to add the apps first before you can use it. It doesn’t work by default for all apps.
Once you have added the apps, return to the main screen and select “Open Sidebar.” This will open the sidebar and show you all the apps that you have added. Select the app you want to launch. You should see the app launch with a window size of half the screen. The second app you launch will show up in the next half of the screen.
You can, of course, decide whether the app shows up in the top or bottom half of the screen by selecting the Up/Down (or Left/Right if your phone is in a landscape orientation) workspace.
Conclusion
As can be seen, this is really useful only if you have a device with a big screen, particularly a phablet or tablet. It will still work on a phone, but the effect won’t be desirable. While XMultiWindow is still in the early stages of development, we have used it without much problem. It won’t work for some system apps, but most of them should work fine. Now you can truly multi-task on your Android device.