how do these platforms allow one to write a single code for multiple mobile phone platforms?
what kind of magic is going on that allows simple javascript to be used in Sencha to produce multi platform app? I am highly skeptical of all the solutions out there. Especially when they are commercial and no one really explains well what goes on under the hood.
Because you write your code using HTML/CSS/JS. PhoneGap now Corona implements the native code that bridges your code (HTML/CSS/JS) with the native code allowing you to call native functionality.