While most stock Android ROMs include features that can only be considered bloatware, once and a while a manufacturer comes up with an innovative and useful feature that they include into their OEM products.
Samsung released their Multi Window on the Note 2, and the Multi Window utility is included with the release of their Premium Suite utilities with their Jelly Bean 4.1.2/4.2.2 update to the Samsung Galaxy S3. But how to use it?
Multi Window is disabled by default on the Galaxy S3 and activating it is very easy. You need to go to Settings > My Device > Display. There you just need to tick the Multi Window box.
Then just hold the Back Button and Multi Window app will open. That’s it. Enjoy two applications opened at the same time.