WordPress Monsters

You can create templates (layout) for your pages to add some blocks of content before/after general content.
Also you can assign your template to custom post type(archive or single), taxonomies, 404 and search results pages, this options can be found in Templates->Settings menu in admin console.
You should use
<pre><code>[wpm-template-content]
</code></pre>
shortcode in this templates to separate content.
Watch how to use Template Manager plugin in this cute short video:
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/jY2T-ZuUfSE?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>

Template Manager by WordPress Monsters

This is a temlate manager plugin for easy WordPress development from scratch when you are use Page Builders plugins.

Thorsten Frommen

Kalimah Apps

Joe Bailey-Roberts

This a Gutenberg plugin that adds an outline around each block. Outline settings are based on user meta. Each user can 
change the settings according to their needs and it will applied only to their account.
Users can change:
<ul>
<li>When to show outline. On hover or always displayed.</li>
<li>Lock outline for a single block.</li>
<li>Disable outline completely.</li>
<li>Show data (name and class) outside block, inside or floating when hovering over block</li>
<li>Change outline color.</li>
<li>Change outline style to solid, dashed or dotted line</li>
<li>Change padding size</li>
<li>Show/hide block name</li>
</ul>
<h3>Filters</h3>
<ul>
<li>editor_outline_default_user_meta 
You can override the default user meta by using this filter. The filter will receive the default user meta as an array and 
you can return a modified array. 
Check github repo for more information. https://github.com/kalimahapps/Editor-Block-Outline#filters</li>
</ul>

Editor Block Outline

Great work. I've been considering making a similar plugin myself, so I'm glad I found this one before I did. It works well and makes it considerably easier to see where each block is. Especially useful when you have blocks within blocks. i.e. Group -> Columns -> Column -> Paragraph

Makes Gutenberg usable

I like this.

When I edit multiple blocks, this plugin help me.

Very useful plugin

Add outline around Gutenberg blocks while editing

Template Manager by WordPress Monsters vs Editor Block Outline