AMPEDUPDESIGNS

When you focus on an input element in iOS, a blue highlight shadow displays when the input field comes into focus.  Searching high and low, the common answer to disable this seems to be by setting the outline:0 in css on focus like:

input:focus {
    outline:0;
} 

It didn't work for me.  What else do you need?  Turn off the box shadowing that iOS also adds like this:

input:focus {
   outline:0;
   box-shadow:0;
   -webkit-box-shadow:0;
   -moz-box-shadow:0;
} 

Hope that helps!