We use Google Apps For Education in our school district and we are managing our Chrome users (and Chrome devices) with the Chrome Admin management console. Within the admin console, we can set up a bunch of policies and tweak settings for our users. We are able to set up preferences in the admin console that limit what apps users can shop for (that option is available for us to set on district user accounts when they shop for apps in the Chrome browser and for Chromebooks). I'm also guessing that since its all user/web based that these preferences should work for Chrome Apps for Mac (since they are logging in with the same Google account and most preferences are set to the user, not the device). I haven't tested this yet, but this is in my list of things to check over the holidays.
If users are logging in with their personal Google account (non school account), I can't think of a way to block that. We'll see...
~Joe
