Easy Update, Important Info Ticker/Banner

Hello,

I am very new to WordPress so I’m slowly learning new things all the time.

Right now I am trying to make a little banner or ticker that will pop up on my website to show users important information.

I’ve been trying to find a plugin with no luck.

I would like it to be visible near the top of the website or on the sidebar.
Also I would like it to be really easy to update. Let’s say a user comes to the website and wants to add or remove a ‘notice.’ They can go to an admin section, type in some login credentials and then be able to update the ‘ticker.’

I basically want it so this plugin or widget can be updated from mobile so the important information can be shared to users ASAP.

Any help is appreciated!

If you need more details or clarity, just ask!