I'm putting together the last menu tutorial for step by step and have discovered a bug in sticky navigation:
http://foundation.zurb.com/sites/docs/s … navigation

There is a problem with iOS on mobile where that effect makes the menu open with a bottom position and throws off the layout. If you want to see it work I'll leave this test up for a day or two so you can see it. You have to open it in your iPhone and click on the menu icon, then you'll find the menu at the bottom.
http://gordw.com/rsd/test/index.html

Even using the script option to openOn medium screens only still doesn't repair it. On git hub they are working on a solution and are aiming for the fix to be in foundation 6.4 meanwhile if you are using the buttonbar menu tutorial take that option out. I'll update that one to resolve the issue.

NOTE ON THE CSS REPAIRS
Also when I write this tutorial up I'll have the RSD CSS repairs needed to fix the accordion menu in mobile and for the drop down on desktop. For now you can get those fixes by viewing the source code on the test menu. I have them commented in the HEAD.

I noticed the bug you mention. Good of you to fix it!