I wouldnt judge My Coloring Book Free by its features and finesse - it gets good scores in these two departments. But the ultimate judge is my kid, who really enjoys it, partially for its measured simpleness and graphical elegance. Recently added pictures help, too. And no sooner as my 6-years-old told me that all were coloured than more pics come.
The latest updates also included new colour picker which even delighted my now 10-years-old. Keep it on!
Sillyvalley about My Coloring Book, v5.2