Sketchbook Pro (US$4.99)
Sketching can be pretty sketchy with just your fingers, turning a potential piece of digital fine art into a doodle that looks like it has been fingerpainted by toddlers.
Your creativity is only limited by your talent on this app. It supports pen pressure sensitivity so your strokes come out exactly the way you want while different tools and effects give more options than your local art store could ever provide you with.
Point of the S Pen: The S Pen puts the fine in fine art. If your artwork still turns out bad, you can only blame your artistic aptitude, or lack thereof.