They are shown in the designer when you expand the component tray, and a lot of people find this view to be useful. I'd recommend leaving it in for now until we can find a good replacement. I think the blurb I dropped [here](https://github.com/mozilla-appmaker/appmaker/pull/1268/files#diff-1ad4cd73067a22c55abdc63c04cb1abeR56) will let you avoid this kind of call.