Bill Erickson
http://www.billerickson.net/advanced-custom-fields-frontend-dependency/
ACF also includes a bunch of functions you can use in your theme to retrieve the values of the meta fields. But I recommend you don’t use these.
There is no reason to use an ACF function like get_field() when you can use a WordPress core function like get_post_meta(). Using these ACF functions introduces what I’m calling “frontend dependency”.
My comment on Bill's blog: ...I’ve been using ACF as you describe, without ACF functions and wrapping functions in a if {function_exists} ( ‘get_field’), etc., The snippets were found within the Genesis community. So, I’m good, phew!