Comment by Jach

I don't buy this. Google has this information on their backend, they don't need to query any local state. Indeed, when I visit a play.google.com URL, google checks if my browser is logged in or not. If it is not, the default is "Install" no matter what. If I do have a session, then it's either "Install" if I don't have it installed, or "Install on more devices" if I do have it installed.