Vladimir Prelovac

<p>The Yahoo! Exceptional Performance team recommends <a href="http://developer.yahoo.com/performance/rules.html#js_bottom" rel="nofollow ugc">placing scripts at the bottom of your page</a> because of the way browsers download components.</p>
<p>“The problem caused by scripts is that they block parallel downloads. The HTTP/1.1 specification suggests that browsers download no more than two components in parallel per hostname. If you serve your images from multiple hostnames, you can get more than two downloads to occur in parallel. While a script is downloading, however, the browser won’t start any other downloads, even on different hostnames.</p>
<p>In some situations it’s not easy to move scripts to the bottom. If, for example, the script uses document.write to insert part of the page’s content, it can’t be moved lower in the page. There might also be scoping issues. In many cases, there are ways to workaround these situations.”</p>
<p>WordPress default behavior is to load javascript in the  page.</p>
<p>This plugin will move all javascript code to the footer if the plugins have <a href="http://www.prelovac.com/vladimir/best-practice-for-adding-javascript-code-to-wordpress-plugin" rel="nofollow ugc">declared javascript properly</a>.</p>
<p>Plugin by <a href="http://www.prelovac.com/vladimir" rel="nofollow ugc">Vladimir Prelovac</a>. Looking for <a href="http://www.prelovac.com/vladimir/services" rel="nofollow ugc">WordPress Services</a>?</p>
<h3>License</h3>
<p>This file is part of Footer JavaScript.</p>
<p>Footer JavaScript is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.</p>
<p>Footer JavaScript is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.</p>
<p>You should have received a copy of the GNU General Public License along with Footer JavaScript. If not, see <a href="http://www.gnu.org/licenses/" rel="nofollow ugc">http://www.gnu.org/licenses/</a>.</p>


JavaScript to Footer

I used and face some of bad experience with it 

Can't give perfect result

This plugin automatically moves JavaScript code to page footer, speeding up page loading time.

Katsushi Kawamori

<p>Add a fixed menu. The basic menu is at the bottom, but it can also be displayed on the top, left, and right.</p>
<h4>Links</h4>
<ul>
<li>Five link destinations can be specified.</li>
<li>Provides filters for icons, URLs, and text for each link.</li>
</ul>
<h4>Options</h4>
<ul>
<li>Can specify the number of columns from 1 to 5.</li>
<li>Can specify the font size with px, rem and em.</li>
<li>Can specify the menu height with px, rem and em.</li>
<li>Can specify the line height with px, rem and em.</li>
<li>Can specify the padding with px, rem and em.</li>
<li>Can specify their class to remove the overlap for headers and footers overlap.</li>
<li>Can specify the color of text, buttons, and overlay.</li>
<li>Can specify the upper limit of the display width.</li>
<li>Can specify the stack order of css elemental.</li>
<li>The above options filters are provided.</li>
</ul>
<h4>Other filters</h4>
<ul>
<li>Provide a filter to erase the menu.</li>
</ul>
<h4>How it works</h4>
<span class="embed-youtube" style="text-align:center; display: block;"><iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/gmTUhSOPw9c?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe></span>
<h4>Live Demo</h4>
<ul>
<li><a href="https://fbm.riverforest-wp.info/" rel="nofollow ugc">Fixed Bottom Menu Live</a></li>
</ul>
<h4>Icons</h4>
<ul>
<li><a href="https://developer.wordpress.org/resource/dashicons/" rel="nofollow ugc">Dashicons</a> can be specified.</li>
</ul>
<h4>Customize</h4>
<ul>
<li>Template files allow for flexible <a href="https://github.com/katsushi-kawamori/Fixed-Bottom-Menu-Templates" rel="nofollow ugc">customization</a>.</li>
<li>The default template file is <code>template/fixedbottommenu-template-html.php</code> and <code>template/fixedbottommenu-template-css.php</code>. Using this as a reference, you can specify a separate template file using the filters below.</li>
</ul>
<pre><code>/** ==================================================
 * Filter for template file of html.
 *
 */
add_filter(
    'fixed_bottom_menu_generate_template_html_file',
    function () {
        $wp_uploads = wp_upload_dir();
        $upload_dir = wp_normalize_path( $wp_uploads['basedir'] );
        $upload_dir = untrailingslashit( $upload_dir );
        return $upload_dir . '/tmp/fixedbottommenu-template-html.php';
    },
    10,
    1
);
</code></pre>
<pre><code>/** ==================================================
 * Filter for template file of css.
 *
 */
add_filter(
    'fixed_bottom_menu_generate_template_css_file',
    function () {
        $wp_uploads = wp_upload_dir();
        $upload_dir = wp_normalize_path( $wp_uploads['basedir'] );
        $upload_dir = untrailingslashit( $upload_dir );
        return $upload_dir . '/tmp/fixedbottommenu-template-css.php';
    },
    10,
    1
);
</code></pre>
<ul>
<li>CSS files can be set separately. Please see the filters below.</li>
</ul>
<pre><code>/** ==================================================
 * Filter for CSS file.
 *
 */
add_filter(
    'fixed_bottom_menu_css_url',
    function () {
        $wp_uploads = wp_upload_dir();
        $upload_url = $wp_uploads['baseurl'];
        if ( is_ssl() ) {
            $upload_url = str_replace( 'http:', 'https:', $upload_url );
        }
        $upload_url = untrailingslashit( $upload_url );
        return $upload_url . '/tmp/fixedbottommenu.css';
    },
    10,
    1
);
</code></pre>


Fixed Bottom Menu

Add a fixed menu. The basic menu is at the bottom, but it can also be displayed on the top, left, and right.

JavaScript to Footer vs Fixed Bottom Menu