Change the wordpress admin design, You can upload your own site logo on that.
Just input your message using the admin panel and the message will display on the frontend of your site on all pages.
You can show a beautiful pop-up Message on the top of the website, the Middle section, and in the footer.
It is very lightweight, it will not increase any load on the website.
With the help of setting you can tune on or off the pop-up for the rest of the pages on the website.
“Compatible with all major browsers, well tested with ie10”