This was done in ArtRage on the Ipad, so it was done digitally. I used the ink pen set on full taper to create the fur. Glad you all like it.
I've had ArtRage for years. I stopped using it, mostly because of the limited canvas size. Thanks to you I just checked the app again, and found that they've upgraded it. You can have up to a 2048 x 2048 canvas.
I'll probably start playing with it again, because, as you've said, ArtRage has the most realistic simulations of physical media. Crayon really looks like crayons. Well, more so than any other sketch app.
If you want the widest range of tools, and all kinds of crazy transform and filter tools, then SketchClub is a must. It's almost too much. Best to start with a few tools you understand and build on them. It's also a social/club style app, so there are lots of other people, art examples, and other resources to draw on (pun intended).
Of course SketchBook Pro is the de-facto standard. It does not have every tool possible, but the tools it does have are well thought out and executed. It's biggest advantage over the other apps is it's cross platform standard. It is available on most platforms, and the drawings can be transferred to the computer or device most convinient or suitable for the drawing.
Other than specialty apps, and vector based apps, these are the drawing apps I'm most likely to use; holding in mind that I'm barely an amateur doodler, let along an artist.