In the past few years, Segmation has developed "Seg-Play" which is a Paint-By-Number program based on their original Segmation plugin. "Seg-Play" is available for PC and Mobile. Each month two new paint sets are offered. The first set is usually Old Masters and the second set is either photos or cartoons. Difficulty ranges widely from "Easy" to very complicated. I especially enjoy "painting" the Old Masters and own many sets. I also like the photos. The Cartoons are great for children but I also own several cartoon sets.
There are several option in Seg-Play and you can paint with a timer if you want a challenge. Each image has a colorful pallette of paints to choose from. You can opt to use the standard color numbering or you can turn that off and paint any way you like. You can change the color of the numbers and the font. You can zoom in. You can paint each color as it comes or you can even paint all of each color one-by-one.
I call this "Color Therapy". It makes me feel better when I get sad and if I am in pain, I don't feel a thing while I am "painting". Admittedly there is little challenge here and almost no creativity (unless you turn the numbers off) but this program (game?) has given me many hours of enjoyment for more than 10 years. The Photoshop plugin is not being sold at the Segmation site and has not been updated in years but may still be purchased on the WEB. Some Game Portals offer Seg-Play PC or Mobile and/or the paint sets in their catalogs. Segmation can also be found at Facebook.