Those are features of Chrome and not really an "app". It is not new for web developers to target specific features of a web browser. I have not qualms about calling Chrome apps that can be ran offline apps. Perhaps I am looking at this from the wrong perspective. For Chrome OS, a link that is acting like an app that you can "Alt+Tab" to would play better into the idea of an app than another tab in your Chrome browser. Almost every "app" on the chrome store I have interacted with has been an app-like icon that is a link to a URL that functions identically in Firefox or other browsers.