I wanted to use font-awesome for arrow icons and didn't know what to do at first. But then I looked into the changes that were made in the html-markup after initialization of fuulpage.js:
original html-markup
<div class="fp-controlArrow fp-prev"></div>
<div class="fp-controlArrow fp-prev"></div>
and using the Raptor's reply to this question about changes in a CSS I've found that it is possible to append a new custom element to an element by default by adding two lines in the script where fullpage() was initialized. Please not that since it seems fullpage doesn't delegate click events on its original elements, once added the new ones you'll have to re-assign.
changes in the script
$(document).ready(function () {
$('#fullpage').fullpage();
// The changes that were made
$('.fp-prev').append('<span class="fa fa-angle-left"></span>');
$('.fp-next').append('<span class="fa fa-angle-right"></span>');
// to gain events control / click event delegation
$('.fp-prev').on('click', function(){ fullpage_api.moveSlideLeft(); });
$('.fp-next').on('click', function(){ fullpage_api.moveSlideRight(); });
});
The result is:
final html-markup
<div class="fp-controlArrow fp-prev">
<span class="fa fa-angle-left"></span>
</div>
<div class="fp-controlArrow fp-prev">
<span class="fa fa-angle-right"></span>
</div>