Firas Abd Alrahman

Once you install WordPress with some plugins and finish customizing your theme, you usually stock with performance issues. 
Installing and configuring a good caching plugin, you will enhance your first byte and website speed, but you getting low rank on google page speed. 
The reason for that, each WordPress plugin come with it\’s assets (js/scss files) and most of them are not really used or required, but WordPress does not offer a way to control those injected files in your themes. 
GSP Assets Manager offer an easy way to list, review and control WordPress assets. 
You can disable, move to the header, move to the footer, toggle async for javascript and WordPress without writing a single code. 
The plugin also offer a live preview for CSS, so you can disable the CSS file and see the result directly on your website before you save, to avoid breaking the website style.

GSP Assets Manager (Easy Live Assets Editor)

GSP Assets Manager will allow you to live review and control WordPress javascript files and stylesheets. Optimize google page speed rank within 5 minu …

Sebastian Pisula

Moves scripts and styles to the footer to decrease page load times. You can exclude to move specific styles and scripts to footer.

GSP Assets Manager (Easy Live Assets Editor) vs Assets to footer