I am looking to see if there is a custom measure tool for Web Apps that will display both the segment length and the total length at the same time just like the measure tool in ArcMap?
others can be found Web AppBuilder Developer Edition - Resource List (updated 5/13/2018)
in any case, it would help others to know the development environment you are using, and if you Move Content to a location that fits, you may get more specific help. E.g.
Web AppBuilder Custom Widgets
Web AppBuilder for ArcGIS (more for the ArcGis online version)
or any number of sub places Web Developers
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