Overall, this is definitely one of the better nonogram apps available. A few minor interface enhancements would make it better, such as enlarging the colour selector and making it more obvious which you have selected. I made many mistakes from fat-thumbing the wrong button. Also, the idea of showing your mistakes and deducting "lives" seems silly for this type of puzzle. Left handed or disabled users would probably welcome a right-hand placement option.
The puzzles are (mostly) in colour, however the app fills the colours automatically, just as if you were solving a B&W puzzle. The puzzles are quite easy. I was able to solve several 15x15 puzzles in just a few minutes each, and Im no whiz.
My biggest gripe, however, is the puzzle art itself. I have not purchased any additional puzzles, but the included ones are not encouraging. In my opinion, colour is actually overused and makes several of the puzzles harder to recognize. If your main interest is simply to solve the puzzles, this may not bother you at all.
However, these issues aside, this app still merits a decent rating, because overall it works quite well and is still fun to use.
SaskatoonMusic about Nonogram: Falcross, v1.4.1