Apps that work with Pencil (that I've tried):
Paper
Tayasui Sketches
Autodesk Sketchbook Pro
Autodesk Graphic
Adobe Draw
Adobe Sketch
Morpholio Trace
uMake
Inspire Pro
Procreate
MS OneNote
Unfortunately, ArtRage for iPad hasn't been updated yet, but if you use Astropad, you can use ArtRage 4 on OS X (as well as any other full blown OS X application)! It's like an RDC client sans the virtual keyboard.
Paper
Tayasui Sketches
Autodesk Sketchbook Pro
Autodesk Graphic
Adobe Draw
Adobe Sketch
Morpholio Trace
uMake
Inspire Pro
Procreate
MS OneNote
Unfortunately, ArtRage for iPad hasn't been updated yet, but if you use Astropad, you can use ArtRage 4 on OS X (as well as any other full blown OS X application)! It's like an RDC client sans the virtual keyboard.