I am trying to implement a Search function for Webapp Builder (developer edition) similar to Flex HeaderController widget in which you can search any REST endpoint entered in the config. I tried the Geocode widget, but it is returning a message of invalid URL when I input my address. Assuming it is looking for a Geocoder address. I'm sure this tool is available, but I could not find it in the forum for the new Webapp.
Version 1.2 of WAB use the Search Widget and not the Geocoder widget anymore. The Search widget allows for searching of layers. Add sources layer > Feature Layer.