How to add google analytics or yandex metrika to the footer for logged out users / guests / visitors?

Just add this code into your functions.php file in your Wordpress template:

add_action('wp_footer', 'goaskle_ga_ym');
function goaskle_ga_ym() {
   if ( !is_user_logged_in() ) { // not for logged in users
?>
    <script type="text/javascript">
      var _gaq = _gaq || [];
      _gaq.push(['_setAccount', 'UA-XXXXXXXX']); // insert your Google Analytics id here
      _gaq.push(['_trackPageview']);
      _gaq.push(['_trackPageLoadTime']);
      (function() {
        var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
        ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
        var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
      })();
    </script>
<?php
   }
}