This is a great tip to run apps on separate windows or just for taking cool app screenshots, like this:
How to open a chromless window
Open Terminal app and type:
open -n -a 'Google Chrome' --args "--app=[URL]"
Where [URL] is the desired URL. e.g:
open -n -a 'Google Chrome' --args "--app=https://www.google.com"
If you’re curious about what those flags do, -n “Open a new instance of the application even if one is already running.”, -a “Opens with the specified application” whatever that means.
Source: @DasSurma on Twitter