FYI, some news about the forthcoming ArcGIS Dashboards beta,
Introducing the Upcoming ArcGIS Dashboards Beta

I will update this blog post when the beta is released in April.
Updated - 4/9/2020
EDIT: ArcGIS Dashboards Beta is now available in ArcGIS Online.
FYI: for more resources go to https://community.esri.com/community/arcgis-dashboards-beta
Enjoy,