Best drawing app for Galaxy Note 2
The best DRAWING application across the board for phones & computers is Autodesk Sketchbook Designer. I have it on my Note 2 & it can easily be exported to photoshop, illustrator, zbrush, Maya, etc, etc. it's also very simple to learn, doesn't need a lot of memory and is bloody cheap...
Notice, I emphasized DRAWING & not painting. Painting is a completely different subject...