FREE - In Google Play
FREE - in Win Phone Store
I like both sides of it.
one day i will study that theory;D, one day....
As an alternative to the Nimzo, you may want to try the King's Indian Defense (KID). Here's a video on the lesser played Na6 variation, just as an example.
GM Perelshteyn hass a lot of videos on you tube on this channel: http://www.youtube.com/user/OnlineChessLessons?feature=watch
Here's another one on the Nimzo-Indian from that same channel: