How to Run apps side-by-side
One of the new features added in Android 7.0 Nougat is the option to run apps side-by-side or one above the other. This view comes in handy when you want to display photos, optimize your social networking, or multitask, although it’s a bit too laggy for gaming.
To set it up, tap the Overview button (the square icon below the screen to the left), and choose which of your recently used apps you want to see. Hold and drag it to the top or left of the display, then choose another open app to appear alongside or under it.
And since we’re already talking about the Overview button, here’s a pro tip: Double-tap rather than single-tap it to quickly switch between the two apps you’ve been using most recently.