Compared to Nikoli paperback Masyu books...
... the quality of the puzzles generated by this app is very low. One thing that mystified me is that "easier" boards have fewer circles and "harder" boards have more. This is backwards. The more circles that are given on the board, the more you know about the loop. Easier boards should have more circles than harder boards, not less. Predictably, the further I went along in this app's puzzle progression, the easier the puzzles became.
Granted, I'm pretty sure Nikoli publishes handcrafted board designs, and this app probably generates them programmatically, but nonetheless this is quite a comedown for someone (like me) who is spoiled on good human-designed Masyu boards. [Whoops, I forgot that the 60 puzzles in this app are fixed, not generated. Oh well, more's the shame that they aren't designed well.]
My recommendation: Skip this app, unless either (a) you're truly desperate for Masyu on your device or (b) you don't care about the dollar price tag.