One option is to use a web slider that can run on any browser and does not need to be hosted if you do not need it.
Take a look at
in my opinion one of the best and more versatile sliders.
It can run on mobile or desktop, have different navigation options, arrows, dots, images, and even drag, can have Html content, and can be ...
Rather than install additional software, just configure the users' clients to pop up a notification when you send a message. For example, on Thunderbird, the add-on FilterQuilla can be configured to run a script or to start a program when email from a specific source arrives.