I don't think patting people on the back is useful but if you really want to help him build something awesome, be specific. Your buttons are ugly because they

I don't think patting people on the back is useful but if you really want to help him build something awesome, be specific. Your buttons are ugly because they are too small, the text is hard to read and the back button is actually slightly wider than the next button, even though they are joined together. Back is also red which tends to denote a destructive action that cannot be undone, a yellow might be better. ^ that is feedback. Saying your buttons are ugly is not helpful feedback.