There are loads of posts about this asking for an answer, most are half right or just don't work.
You can use the example nav-bar and add acouple of edits which will be in the answer below.
simply copy and paste the Foundation top-bar example from here. Put this in your HTML,
<ul class="left">' or '<ul class="right">
<h1><a href="#">Top Bar Title </a></h1>
from the title section.Add
.top-bar-section ul {display: table; margin: 0 auto;}
.top-bar-section ul li {display: table-cell;}
in
@media only screen and (min-width: 58.75em) {
Just before the }
closing tag.
This should now leave you with 3 buttons if you chose the left side and it should be perfectly centered