Now I understood your instructions and installed Visual Composer. It all worked fine (please see Figure 1). Such a very powerfull tool !
Now it is working fine on a Computer screen and on SmartPhones.
Regarding SmartPhones, it is still showing the widgets at the end of scroll (please see Figure 2), although I insert the code snippet you told me to do.
Figure 1: http://www.olharrefletido.com/misc/jedtheme-Providing-Better-Look-and-Navigation-Shows-Computer.jpg
Figure 2: http://www.olharrefletido.com/misc/jedtheme-Providing-Better-Look-and-Navigation-Shows-SmartPhone.jpg