What I don't get is what does MagicJack get you that, say, Google Voice doesn't do? But then, I never have understood the attraction of them.
To my mind, it makes more sense to buy, for a one-time fee, the
OBi (there are other options I believe) which can be used with a number of different VOIP services, including the free ones, of which the best known is Google Voice.
Also, you can use Google's Google Voice app for Android and iOS.
Basically, MagicJack preys on people who don't know about their options.
Also, they are late to the game if they only just got an app...