Mitchell Lunafish
Not bad, could be better. I love that you can add your own collection of tsumegos. But the app really needs some user friendliness such as a more logical way to exit out of a problem set and return to the main menu. (Home button?) Also, one thing I wish would be changed is the automatic failure of a problem if, after having successfully solved it, you continue to place stones down to try out different things beyond the problem. Another app, Tsumego Pro, allows you to do this without penalty.