Two months back Google made developer preview of Chrome Packaged Apps and Chrome App Launcher available for testing. But that time to install any Chrome Packaged App you need direct link of it and you can’t get it by browsing or searching in the store. Today Chrome team has avoided this difficulty for you by offering a dedicated category “Apps” for Chrome Packaged Apps in store for dev. channel users on Windows and Chrome OS.
Google offering these Apps for Dev.channel only because they’re still under testing. And another new category “websites” below Apps category offers all legacy and packaged apps. You can try Chrome Packaged Apps on Chrome Web Store here, to install these apps you need to sign into your Google account.
Source: Chromium blog