Every so often I come across drawings I have done on the computer, this was part of a drawing challenge a few years ago. You would work from a reference photo someone posted on line (in this case a site called Sketchfu that has since closed). Then a group of artists would draw the image using the tools on the site, which were a palette of about 100 colours, a colour picker, about 5 different sized pens, a control of opacity, and I think there was also an eraser.
The tools were minimal but enough to be able to create quite good images. I wish the site was still working. I spent a lot of time there. The shock when the owners decided to close it. I know several thousand users were distraught, they had invested so much time in it. I had downloaded a lot of my work but I know a lot if people lost everything.