Multi window supported Android devices (without root)
I'm not absolutely sure, but I believe that that is a feature of Samsung's TouchWiz (proprietary build of Android) and only works select Samsung tablets/phones, among them the Galaxy S5/4, Note 3. The LG G Flex also boasts to have "Dual Window", and LG G Pro 2 has QSlide for limited multitasking.

Other aftermarket Android projects are working on it (OmniROM, ParanoidAndroid) but that still requires a rooted device.

The next best thing are "floating" apps, like Floating Apps (free, $1.99) or Tiny Apps (free, $2.03). These apps create smaller windows that float over all other applications allowing you to interact with multiple apps simultaneously.