Depends on which carrier you have.
It is not available on the Verizon models.
Did you get in here late?
I just posted how to a few posts back.
This from the manual.
Using the smart scroll feature
Set the device to scroll the screen up or down by tilting your head or the device. You can use
this feature while viewing emails or webpages.
On the Apps screen, tap Settings → Accessibility → Dexterity and interaction → Smart
scroll, and then drag the Smart scroll switch to the right.
Use the following options:
• Tilting head: Set the device to scroll the screen up or down when you tilt your head
upwards or downwards.
• Tilting device: Set the device to scroll the screen up or down when you tilt the device
forwards or backwards.
• Speed: Adjust the speed for scrolling the screen.
• Visual feedback display: Set the device to display a visual feedback icon when the device
recognises your action.
Get the manul here:
* PDF manual from Samsung - Android Forums