Followed the tutorial using the OpenGeo suite SDK, and looking at adding a scale to my maps however the tutorial doesn't cover adding widgets only plugins. So I am not sure about how I would add http://gxp.opengeo.org/master/doc/lib/widgets/ScaleOverlay.html wherever I place it fr example the tools section I seem to just get a white screen, which tells me something is wrong.
I believe I should call it using
* @require widgets/ScaleOverlay.js
and then as with plugins something like (below) in the tools part of app.js