Follow along with the video below to see how to install our site as a web app on your home screen.
Note: this_feature_currently_requires_accessing_site_using_safari
Either one works...but for different purposes...and for different products or brands.
There really isn't a "black and white" set of rules to follow...just set up a profile at both and start contributing content...to their discussions (not promoting your own stuff at first)...test and find out which one is better for you.