diennk

By default our browsers have scroll not smooth. It seem lag when mouse wheel.
A plugin was make browser’s scroll smoother.
No settings required. Just install plugin and active it then see your scroll bar scroll smoother

Smooth Scroll

By default our browsers have scroll not smooth. It seem lag when mouse wheel. A plugin was make browser's scroll smoother.

renp

A simple WordPress plugin which adds a “scroll to top” button to the bottom corner of the page if the page has been scrolled down. It is compatible with all major browsers and should work with all themes, including 
responsive and high resolution themes.
It is possible to configure the plugin in the admin area for choosing between light or dark colour schemes and size of the button as well.
If your theme doesn’t already contain this feature, you can simply add it by means of this plugin.

Scroll to Top Button

Displays a button in the bottom right corner for smooth scrolling to the top of the page.

Smooth Scroll vs Scroll to Top Button