This is the demo page that shows all of gaia web components.
To view the result on desktop, open your Firefox Browser and enable dom.webcomponents.enabled preference in about:config.
To view the result on FirefoxOS device, connect your device and open WebIDE in desktop, choose preference table from option menu to enable dom.webcomponents.enabled preference on device.
You can check Is Gaia Components Ready page to track current gaia web components status.