Till now to get Chrome App Launcher on Windows you need to install any packaged app in Chrome browser like test drive or CIRC and have to enable related flags in Chrome://flags page and restart the browser. Seems this not any more needed as latest update for Dev. build has added shortcut for Chrome App launcher on Windows start menu that means App Launcher no more an experimental feature (?).

You can now quickly access Chrome App Launcher from Start Menu in Windows. Of course, you need to signed into your  Google account for app launcher to display all installed apps.

Google Chrome App Launcher shortcut Windows Start Menu

Update: This Shortcut also available on Desktop as well.