On Github chen7012 / UC-2016-Tips-Trikcs-WAB
Web AppBuilder for ArcGIS is built with ArcGIS API for JavaScript and Dojo. It allows you to customize and extend functionalities by creating your own widgets and themes.
Installation
Two types of widgets are supported: an off-panel widget (such as Scalebar widget) and an in-panel widget (such as Query widget).
Create a custom in-panel widget