I actually found a kind of solution, if anybody found this post interesting.
I make one front page for both computer, tablet and iphone. And then i use extra class name tags, to define which content to show on each device.
I use these tags: http://getbootstrap.com/css/#responsive-utilities-classes
Fx. if i only want to show on tablets and smartphones, if put these tags
in my extra class name: hidden-kg hidden-md —— I can also use the visible tags. This tag is for showing content only on my smart phone: visible-xs
If i want to show only on larger screens, I use these tags: hidden-sm hidden-xs
Hope this post can be helpful, if anybody have same issue.
/Jeppe