Your book appears to be oriented to iPhone, including comments about keeping apps very simple, both in screen and data processing. What about the iPad? I have a complicated Windows application that I would like to port to iPad. Should I use Touch 2 or Ext JS 4?

Phone applications tend to be simpler to develop, and posting photos of the phone is generally easier to do.

That said, Ext JS is * not * a framework for mobile app development. Sencha Touch 2.0 is the best solution.

The way you develop apps for Phone or Tablet really doesn't differ that much. I'll be discussing some of this in the last chapter, where I will cover Sencha Cmd, MVC and Native packaging.