Useful phone game for painting?

Abstraction

I try to avoid games on my phone, but I found this seems helpful for training my eye to pick value and colour subtleties when they are out of context.

  

tassieguy

@Abstraction, it looks useful and fun. What's this called and where can we get it? I've tried to find it from the image but no luck and there's nothing I can see in the image to tell us where it comes from. 

Abstraction

'Color Puzzle:Offline Hue Game' by simplelife studio. I have no connection with them, just saying.