The official app & game
Distributed by ApkOnline
Download this app named Screens.Screens allows you to quickly enter splitscreen mode with pre selected apps. It creates shortcuts that can be used from any launcher. This might be good for productivity or having SeriesGuide and Kore at the same time.
This app uses Accessibility services. Accessibility services are required to enable Multi window automatically, if you don't want to provide this open source app with the permission you will need to manually hold the recents button when prompted.
Updates:Testing: Android 8 support
Added an adaptive Icon and now uses a dark theme
Screens from ApkOnline.net