kameleonosis

Visual Tools adds a customizable control panel for admins to apply global visual changes — such as font size, spacing, background and text color — across the entire website.

visual-tools-front-end-panel

Provides global visual customization (font size, spacing, colors) for WordPress admins, with live preview.

chandra sekhar Gudavalli

This plugin will enable increase the font size of the page for better reading experience 
Once we activate this plugin, it will automatically display a widget in “Available Widgets” section.

Simple Zoomer

This plugin will enable increase the font size of the page for better reading experience.

visual-tools-front-end-panel vs Simple Zoomer