6.3.9:

-New Navigator in Tools
-Double tap Navigator or Reference images to flip them
-Fixed low flow burning and banding

6.3:

-160 new brushes (the old brushes are located in the Legacy folder)
-Create and organize brush folders

6.2:

-Live tolerance: drag with the Fill tool or the Magic Wand to dynamically select the area you want to fill.
-Shape detection: hold at the end of a stroke to snap it into a shape. Tap the shape to edit it.