Modules
Convert Bundles
Convert entity bundles.
Book
Create hierarchical books with content as pages.
Provides some UI for navigating and editing pages.
Removed from core in Drupal 11.
Redirects Fixer
Correct chained redirects.
Add Content by Bundle Views Area Plugin
Integrated with Form Mode Control.
Similar to Views Add Button.
Field Validation
Configure field validation.
Can check for unique title.
Shows a message, see Unique Field Ajax module for clientside indicator.
Ckeditor5 Entity Browser
Adds the ability to embed entities in CKEditor without using Entity Embed.
Enhances the normal link button.
Uses Entity Browser module.
Flag Lists
Use flags to create personal lists of content.
Entityqueue
Create lists of entities.
Content Browser
Pre-configured Entity Browser for node content.
Use as a working starting point for your own configuration.