Webflow does not offer a Mac app. There is a solution at present that is entirely free. Other posts have been shared about this solution. This one is using the service of nativefier. The source code and information is available on Github, if you perform a quick search. In sum, if you have homebrew installed it is dead simple.
what would be the reason for doing that?
The main reason is to avoid distractions from the browser, in my case Chrome.
Using the app allows better usage also with my system to allow increased focus on working with Webflow.