If you are currently testing OS X El Capitan, please back up your Mac and do the following to install the GM Candidate. Go to your Purchased tab in the Mac App Store and click the Download button next to OS X El Capitan GM Candidate. Then click Continue to download the full OS X installer. When your download finishes, the installer will automatically launch. Follow the onscreen instructions to complete installation.
Split screen mode was something that I very rarely used on windows and had completely forgotten about it on the latest version of OS X El capitan. It was only an update to Blogo which now supports El Cap split screen mode that reminded me to give it a go.
One star reviews might be a thing of the past, or at least not so prevelant when El Cap comes to launch thanks to this one simple notification.