Vladimir Prelovac

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.
“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.
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.”
WordPress default behavior is to load javascript in the page.
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>.
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>?
<h3>License</h3>
This file is part of Footer JavaScript.
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.
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.
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>.

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.

Silkalns

WP Chill

Remove or replace footer credits (or any text or HTML in page) before page is rendered. With this plugin there is no need to modify code such as footer.php which if done incorrectly can cause your site to break or new theme updates will stomp over your changes requiring you to remove footer credits on each update.
This plugin has very minimal options to keep things simple and easier to use. You enter the text or HTML that you would like to find in one text box and the text or HTML that you would like to replace in another text box (or nothing to remove). Go <a href="https://cpothemes.com/remove-powered-by-wordpress/" rel="nofollow ugc">here</a> to view my step by step tutorial with screenshots and video.

Remove Footer Credit

It seems to work, but not as intuitive as it should be. You need to copy the code that makes up the footer porting you wish to move and paste that into the box. Wish there as a way to simply way to remove it.

Seems to Do Nothing

Remove or change footer credits or any text or HTML without modifying code.

JavaScript to Footer vs Remove Footer Credit