Dave Ryan

Create chat threads using WordPress Blocks inside app and mobile wrappers.
Chatterbox can be used for: 
* Demos of chat bots 
* Publishing chat records in news stories 
* A fun way to add striking visual display to conversations
At launch, Chatterbox allows display of chats with messages and timestamps in inbound and outbound styles.
Chat threads can be displayed without a background, in an app container, in mobile phones and other computer screens.
Learn more about what’s <a href="https://github.com/0aveRyan/chatterbox#roadmap" rel="nofollow ugc">on the roadmap</a>.

Chatterbox

Create chat threads using WordPress Blocks inside app and mobile wrappers.

Jonathan Bardo

Note: This plugin only works with WordPress 4.2 or higher
This plugin will enable the site administrator to easily create an admin message present on all pages. The admin has the option to let the user dismiss the message for the duration of his session.

Admin User Message

This does just what I want. Thanks for making it. :)
It's definitely better than https://wordpress.org/plugins/admin-screen-messages
You might want to also tag it as:
https://wordpress.org/plugins/tags/admin-message



Perfect

Add message to users of your site. Choose wheter they can dismiss it or not.

Chatterbox vs Admin User Message