MythThrazz

The plugin is very simple and it doesn’t come with any changable options.
The only feature it has is ability to detect the AdBlock (tested on Chrome AdBlock extension) and defines the HTML class allowing to control the visibility of 
the elements on your page based on the detection result eg. you can show an element on your page only if AdBlock is detected, or hide it.

Tiny Simple AdBlock Detector

Detects AdBlocking software and allows to display some html based on detection result. Word for AdBlock for sure. Should work for others.

Element Invader

Ivica Delic

The plugin analyzes your pages and posts to find all Gutenberg Blocks that are used, not used or missing on certain pages and posts.
This will help you to remove unused Gutenberg Blocks and optimize the speed of your website related to Gutenberg Block Editor.
Or to Detect Missing Gutenberg Blocks from accidentally deleted plugins on posts or pages.
Plugin also showing Blocks Position on specific page at same time to quickly find where exactly widblocks are used.

Blocks Detector Finder

Detect / Find Gutenberg Blocks used on pages, also detect not used Gutenberg Blocks or Missing Gutenberg Blocks.

Tiny Simple AdBlock Detector vs Blocks Detector Finder