WebSite-Watcher is a native Windows software.
If you want to use WebSite-Watcher on Mac, Linux or Chrome OS, you have to use a tool like CrossOver or a Virtual Machine.
If you don't already have a Virtual Machine that runs Windows, then a tool like CrossOver might be a comfortable solution to run WebSite-Watcher. With CrossOver, WebSite-Watcher runs on Mac, Linux and Chrome OS.
CrossOver can be found at https://www.codeweavers.com