Back in February 2015, Tim Witt released a modified Coordinate widget that also shows current map scale. I took the scale-related elements of that widget and added them to the Esri Coordinate widget released with WAB Developer Edition 2.2.
Here's a screenshot of the widget working in an app made using WAB Dev 2.2. Note that this shot is from Firefox browser (it will appear this way in Chrome as well). If IE11 is used, the scale will appear on same line as lat/long coordinates.
To install, unzip and place "Coordinate" folder in the widget folder of your WAB Dev 2.2 app after