Thanks for this plugin, it's just what I was looking for and it works great :-)
Can I make one suggestion to improve it's accessibility?
In gf.placeholders.js the display of the label is set to none:
var $labels = $('label[for=' + id + ']').hide();
This means that for people using a screen reader, the label is also skipped and the relation label-input field is lost. That way a form gets unreadable for a screen reader user.
Maybe it's a better solution to hide the label using CSS adding a screen-reader-text class like
More info about this you can find at: