SketchBook Pro
Autodesk
Free - $5/mo or $30/yr
Current version: 8.2.3
Features:
· Distort transform
· Advanced perspective guides
· Synthetic and blending brush types
· Enhanced selection
· Dynamic gradient fill
· Flipbook animation
· Copic color library
Observations:
A fantastic desktop application for a low annual subscription amount that sadly lacks the pen mode found the Windows Store version. At least it includes selection tools mysteriously omitted from the app.
The desktop UI is a bit more crowded but is still very useable on a Surface Pro 4.