show specific number of posts on front page for mobile d7
I ended up just redirecting the mobile devices to mobile front page(view), 
I was trying to avoid this, but it does not seem to be much trouble.

Add this code near the top of MYTHEME/page.tpl.php

&lt;?php if ($is_mobile == TRUE &amp;&amp; drupal_is_front_page()): 
drupal_goto('/mobile');
endif;
?&gt;


Then you can adjust the pager, number of posts etc. I suppose this 
is a workaround not an answer.