Hi,
We have used a few of Robert's Robert Scheitlin, GISP custom widgets in our web maps using ArcGIS Viewer for Flex. With that program being retired we are switching all of our web maps over to Web App Builder hosted on ArcGIS Online.
One of the nice things I like about WAB is that it is hosted on AGO. Before with flex, our maps were internal only and couldn't be accessed outside the network. With WAB since it is hosted on AGO all of our applications can be accessed outside of our network, which is great for our field crews and managers when they are in meetings or outside in the field.
