How to turn on Motion & gestures in Samsung Galaxy S8+?

The Motion settings lets you interact your device with natural movements of the device or by moving or touching the screen. 
 

Navigate to Apps screen → Settings → Advanced features → Smart Stay

Pictorial representation of the above settings are as follows :  

a). From a Home screen, swipe up or down to access the Apps screen.

b). Touch Settings.

c). Touch Advanced features.

d). To turn on/off the desired advanced features, touch the sliders. For this example, touch the slider next to Smart stay.

CLICK HERE to know about turn on/off Auto rotate in Samsung Galaxy S8+ ( SM-G955 ).