What is Smart Switch?
Smart Switch is a built-in application on Samsung Galaxy devices that allows you to seamlessly transfer data from your old device to your new Samsung.
Smart Switch will transfer data from most Android or iOS phones, and even some older Windows and Blackberry devices. 

NoteSmart Switch lets you transfer content from old phones to Galaxy devices only. For example, you cannot transfer content to an iOS device. The supported items may change depending on the connected device.

I can’t find the Smart Switch app on my phone.
Settings->Search “Smart Switch” OR Settings->Apps
If you still can’t locate it on your device, you can download it from the Google Play Store
Watch a Video Tutorial
Click Smart Switch Tutorial to watch a helpful video tutorial.